Find answers to common screen printing questions.

EQUIPMENT

Quality is in the eye of the beholder. Some people buy their prints by the pound and if they are not thick and shiny, then they think it is a bad-quality print. Other people feel if you can’t feel a breeze through the print then is not a good-quality print so who is to define what is a good-quality print is?

In general, the print should feel as much like the garment as possible and be comfortable to wear. In that case, the automatic always does the better job because it doesn’t have the human factor. Human beings have distractions and get tired. The key to getting a good print is consistent speed, angle, and pressure. If you ride the blade of the squeegee on the print edge then you are going to get a good print through the proper mesh. A human being isn’t capable of doing that for any sustained period of time.

The other element, which also is related to our human frailty, is that most prints should be done with finer meshes. The most common mesh in a manual screen print shop is 110 monofilament and that is the worst possible mesh for printing anything, except for white football numbers.

Nothing should be printed with 110, but people print with screens that are not tensioned tightly enough and they get tired. It is a lot easier to force ink through a 110 mesh. It produces a bulletproof print and you get the buildup problems on the back of the screens, which causes fuzzy edges wherever there are overlapping ink colors.

These are all the things that cause that visual difference between a print on a manual vs. a print on an automatic. Technically, you can do the exact same print on a manual as an automatic but, you have to be consistent and a human being is just not as consistent as a machine.

The reason rubber is added to aluminum platens is to soften the printing surface. This results in a better ink deposit. When a room temperature aluminum platen is used under a flash cure, initially it draws heat away from the shirt, which results in a longer flash time.

However, an aluminum platen heats up after repeated use under a flash cure, and it retains that heat. It gets so hot, it may cure the ink in the screen, which you don’t want. So a rubber top helps dissipate the heat more rapidly eliminating this problem

A rubber-coated aluminum platen is more expensive and messier. No matter who you buy it from, the rubber doesn’t stay on the platen forever. Eventually it delaminates so you have to buy replacement rubber and glue it back on yourself. When reapplying it, you have to make sure it doesn’t get air bubbles. You can send your platens back to the manufacturer for resurfacing but that becomes expensive. Workhorse offers both types: uncoated aluminum and rubber coated. It’s a personal preference. If you want to buy the replacement rubber, two supply houses that carry it are:

Action Engineering
4761-H Hugh Howell Road
Tucker, GA 30084
800-228-4668
sales@actionengineering.com
http://www.actionengineering.com

A.W.T. World Trade Inc.
4321 N. Knox Avenue
Chicago, IL 60641 USA
773-777-7100
Fax: 773-777-0909
sales@awt-gpi.com
http://www.awt-gpi.com

Construction is everything when evaluating which presses are the most durable. A manual press has to be made out of structural steel tubing. You can’t make a strong manual press out of sheet metal, it just doesn’t work no matter how good of an engineer you are, and there are presses on the market made of sheet metal.

Another key component is the center shaft. This is the axle that everything turns on. A better-quality press will have a 2.5-inch center shaft and truck bearings to turn the machine. These are designed to take the wear and tear and roughness of driving a truck over bumpy roads at 60 miles an hour.

When used on a rotary manual screen printing press, there is no way that these bearings will have a comparable load on them even after 20 years of use that the truck would.

Once you’ve got that solid center shaft, you must have good structural support under the print arms where your platens are connected. These must be supported to eliminate deflection. Without some kind of structure under there no matter how good your arm is or the type of material it is made out, it is going to bend downwards away from your screen when you put heavy downward squeegee force on it. So that is really a critical factor.

The print head should be made out of a light, but sturdy material like the type of aluminum used for landing gear on Boeing aircraft. It is strong and it doesn’t give or flex. It’s also very accurate. When you machine it to a tolerance, it stays that way forever. It is more expensive than other materials, but it is the right way to do it.

Visually it is going to be difficult to tell how sturdy a press is. Your best test is to physically walk up to a shirt board and put both hands on it like you are doing CPR on somebody’s chest and push downward on the shirt board. If that shirt board moves in a downward direction, it’s not a sturdy press.

Feel it yourself. Don’t fall for somebody sitting on the platen and rotating around in a circle because all this means is it’s already been deflected it down and now they are riding around in a circle on it.

Whether or not you have to buy a bigger dryer will depend on the size of the one you already have. If you want to get the maximum speed out of your press, you may need a bigger dryer.

If your dryer can handle only 100 shirts an hour and your press is set up and running 300 shirts an hour, you’ve got an issue. But, if you’re running a foot pedal and you’re running a machine for your own quality of life, you can hit the foot pedal and put a shirt on the dryer at your dryer’s pace. You’re still avoiding carpal tunnel because you are not pulling a squeegee.

If you have a small exposure unit, most likely you’re going to need a bigger one. Automatic screens are 23 x 31 inches and your exposure unit must be able to fit that size of screen.

A gas dryer is not totally necessary. What you need to have is heat, and this possible to achieve with a flash cure.

The big trick with discharge is the longer it stays wet and in the dryer, the more vibrant the colors. However, for a lot of the jobs these days, they don’t want vibrant colors they want that grudge retro look. In this circumstance, you don’t have to use as much ZFS or activator. I like the look when it doesn’t fully discharge.

You may have to run a discharge print through an electric dryer more than one time.

You definitely have to slow down your belt speed. Plastisol cures from the top down, which is the biggest difference between plastisol and discharge, (water based). Waterbase cures from the outside in. The more you can break up your image, the faster you can get it to discharge. If the design is a big solid, it will be hard to break into pieces and it’s not going to cure quickly.

The first consideration when switching from a metal halide exposure unit to a LED has to do with what type of emulsion your shop uses. You need to be aware that LED exposure units have a very narrow nanometer range when used with dual cure emulsions and most are not in the range best suited for dual cure. Metal halide units have a wide, forgiving range that runs from approximately 360 to 410.
That being said, if you do not use dual cure emulsions, LEDs offer some distinct advantages that should be considered.
The bulbs on LEDs will last in the neighborhood 50,000 hours with no noticeable light degradation. The light is as good on the first second as it is at the end of its life. Metal halide bulbs begin to degrade from the first time you use them and weaken with age. So at some point, you may have to increase your exposure time by a minute, 1:15, 1:45 until you decide to put in a new bulb.
LEDs use very little power compared to metal halide. When using an LED, you might be looking at 5 or 6 amps per usage as compared to 12 amps with metal halide.
A metal halide unit has to warm up before it is fully functional. For this reason, many shops leave it on all day so there is no wait time each time it is used. LEDs are instant on and instant off. No power is consumed between each usage, and there is no wait time. This also lessens its overall power consumption.
If you use a dual cure emulsion, a metal halide provides a sharper image than an LED. However, unless your shop prints highly detailed artwork, this additional quality may be overkill.
An LED unit is best used for short, fast runs when you are doing a lot of setups and teardowns. An LED paired with a photo polymer may be faster than a metal halide when doing this type of work.
When you purchase a flash cure that is designed to work with a specific brand of screen printing press—and most if not all press manufacturers offer one—what you get is time savings and more control. When a brand-specific flash is plugged in, the onboard computer immediately recognizes it is there, and it turns off that head.
When using a universal type flash, you must manually go to that station to turn off the head. If you forget and start the press, the print head could run into the flash cure unit.
The second advantage is you can control one or more flash cure units from one control panel. You can set temperature, dwell time, and other controls without moving from the same spot. With a universal flash, you must walk to each print head and set the controls.
The brand-specific flash cure unit is less expensive than a universal, which requires a photo cell to detect motion and to know when to turn the flash on and off.
One advantage a universal flash offers is the ability to use it with an automatic and a manual press.
One consideration when choosing a screen drying cabinet is going to be its size. You want a unit that will fit the screen sizes you use. So if you use manual and automatic screens, you’ll want a cabinet that will fit both. They also come in different sizes so you may want a 10-screen size vs. a five-screen size.
A nice feature to have is a slide over the exhaust. When you close off the exhaust, it creates a pressurized cabinet vs. when it’s open it’s unpressurized. If you are located in Phoenix, you will want to leave it open to let in as much hot, dry air as possible for faster drying. If it is winter in Michigan, you will want to leave it closed to keep the hot air inside.
The filtration system is another consideration, however, unless you have a dirty shop with a lot of dust and lint in the air, most filters are industrial grade and will prevent most debris from getting inside.
If you are crunched for space, some manufacturers offer a modular unit that allows you to put the exposure until on top. This makes for a smaller footprint, and it saves manpower to simply take dried screens from the cabinet and place them in the exposure unit without taking a step.
Roughly 50% of presses on the market have pneumatic drives and 50% are servo. The drive mechanism is what rotates the press around. A lot of people confuse the drive mechanism with registration. How well a press registers is independent of its drive mechanism.

Both drive systems use air cylinders to raise and lower the mechanical engagement of pallets to screens. Air cylinders do a good job of accelerating during the index, but have difficulty in the deceleration phase, most systems use some form of external mechanism to assist in the deceleration of the inertial load created by the weight of the pallet arms. How the drive handles the deceleration is the biggest difference between a pneumatic and a servo.

A pneumatic system uses less-expensive hardware than a servo system so it costs less, and it also is easier to repair. In fact, many printers can do the repairs themselves. A servo system is more expensive and generally requires a technician to repair it, so repair costs are higher. In most cases a servo drive costs anywhere from $3,000 to $5,000 more than a pneumatic drive.

The advantage of the servo drive over the pneumatic is performance. A servo drive adjusts to changes in conditions. You can change out the pallet from a sleeve size to a jumbo size with no mechanical adjustments. The servo automatically adjusts itself based on the pallet size selection. With a pneumatic drive, you would need to adjust the press to accommodate the different pallet and/or job weights. Although pneumatic indexing has become more sophisticated over the years, it still requires the turning of a knob or a screw.

PRINTING TECHNIQUES

This is a Ford vs. Chevrolet issue. It doesn’t matter if you push or pull. All automatic presses, such as the Sabre or Freedom Express, will push or pull whichever you would prefer. It comes down to personal preference. The key is doing it the same way consistently because you will get fabric stretch if you do it both ways.

Some people build their muscles to push and others to pull. The best thing to do is to buy an automatic press and don’t push or pull because it is physically hard on your body no matter how you do it.

Jackets are a great business. Many people are afraid of this issue because the minimum cost on a jacket is $17 and up, so it is expensive if you mess it up.

The key to printing a jacket is to use a good jacket hold-down unit. To prevent registration problems, preshrink the jacket before you put ink on it.

To preshrink the jacket, it should be at a higher temperature for a bit longer period of time than when flashing to gel the ink’s surface. You never want to flash cure a jacket too high because it can melt or burn. A good rule of thumb is to flash at around 260-270 degrees for 20-25 seconds. When flashing the ink avoid letting the temperature exceed 190-210 degrees, and the duration should be between 7-10 seconds.

The best way to print jackets on a rotary-load manual press is to set your flash cure immediately to the station adjacent to your printing position, whether that’s left or right. Then have a couple of cooling stops before the jacket gets back to you. You don’t want to bring that screen down on a hot print. A lot of times you may test the print with your finger and think that it is under flashed because it is still hot. The key to quick flashing is to make sure that it is cooled before you touch it.

There is a cost to learning how to do it, but once you master printing on jackets, you gain more business because there are other printers who don’t want to touch it. You also can make more money on jackets because they are more difficult to print.

If you have enough time and a high enough volume order, you can do a jacket panel program. The manufacturer ships the jacket back panels, you print them, and send them back to be assembled. It’s generally a six-week process so it won’t work for short-run orders. But if you mess up a jacket panel it’s only a scrap of fabric, so much less risk.

Most silk is printed with dye. Nylobond with plastisol will never air dry. It will cake up and get harder, but it will not stick. So without heat setting it, you cannot use a plastisol ink. Because silk is heat sensitive, you need to need to use an air dry product. These are usually water based, but there are some solvent-based dyes. If you call ink companies and ask for a fabric dye that is going to be your best bet.
That is an age-old question whenever someone is printing white on darks, red, and navy. Polyester is difficult to print because it is a synthetic. It is dyed through a fiber reactive process and that dye is released when it’s reheated. Ink requires heat to cure it and so when you reheat the garment, it bleeds.

That is why all ink companies work diligently to make low-bleed inks. Low bleed inks, also known as polyester base or poly inks, have a chemical structure designed to help remove some of the color from under the ink and block it.. The trick then is to get the ink cured.

A lot of people don’t want to overcure the ink for fear of dye migration. However, if you don’t make the plastisol solid by completely curing it, you get a leaching effect that takes place in the under cured plastisol. The plasticizer, liquid portion of the plastisol remains, and dye migration (post bleeding) happens 10 times faster.

So if you are using a low-bleed ink, more heat may be better although that would be the opposite of what you might be thinking.

The trick to printing polyester is to run the shirts through your dryer before you print them to drive off the lion’s share of that excess gas. Make sure that you get the ink completely cured and use an ink that has been designed to be printed on polyester.

That is correct. A harder squeegee will hold a greater amount of detail, but give you less coverage. So using a harder squeegee through a course mesh will help save the day in that particular situation. Will it be 100% as good? Probably not, but it will definitely head you in the right direction.
The simple answer is that too much heat causes scorching. To eliminate scorching problems, you need a reliable dryer or flash cure with good temperature controls. Inks cure at relativity the same temperature, but the temperature can vary depending on the color and thickness of the shirt. Also, a white shirt cures at a slightly different temperature then a black shirt due to the thickness of the ink deposit applied.

In general, when curing ink it’s better to err on the hotter side instead of the cooler side, but a white shirt won’t always tolerate temperatures as high as a black shirt will take. When curing you have to take into consideration the amount of ink deposit, and how hot you can go without overdoing it.

In the case of a white T-shirt, 300 to 310 degrees Fahrenheit is all that you are going to need if you are printing properly, and that means you are not printing everything with 110 mesh. On a white T-shirt, if you are printing with 160, 180, or 200 monofilament mesh, you are going to have a fairly thin ink deposit, and it is going to cure beautifully at 290 degrees. So there’s not much of a chance you are going to scorch the shirt there.

If you are printing an athletic print with a heavy ink deposit on a black shirt and using a 110, 86, 60, 30 monofilament mesh, the temperature will need to be in the 340 to 350 degree Fahrenheit range because the ink is thicker and will take a higher temperature to get to the bottom of the ink deposit.

Curing is a cumulative process. If you are printing on a very temperature-sensitive fabric like Spandex, you may need to lower the dryer temperature and run the garments through twice.

Make sure the ink is reaching the right temperature to cure.This isn’t possible by just simply looking for smoke coming off the shirt. You should use a probe to accurately test the ink temperature. In general, if you are running the dryer at 290 degrees, you will not scorch the garment.

There is some truth to this. Today, most T-shirts made by brand-name manufacturers are not too prone to scorching. However, there may be some imported T-shirts that could cause problems. Sometimes to pass custom requirements, suppliers would treat shirts with sizing to save costs. This can turn yellow at a low temperature making it appear that the shirt was scorched when it was simply the discoloration of the sizing. However, this problem is pretty much obsolete.
There are a couple of tricks. The most common technique is using a diluted solution of hydrogen peroxide. Go to your drug store and get a bottle of hydrogen peroxide and mix it at a 4% to 6% concentration in a gallon of water. Soak your shirt in the peroxide-water mixture and this will remove some of the yellowing like a bleaching effect. There are companies that sell a product under the brand name of Scorch Out. I can’t say if it works any better.

INK

There are a lot of jobs that we call, “cotton white.” When printing on cotton there are no bleeding issues. The ink doesn’t have to have the same opacity. You can add up to 25% curable reducer for non-critical jobs. However, when you have a 50/50 shirt, especially when you need bleed resistance, then you can’t keep increasing the reducer.

This answer is brought to you by, Bob Drake who is president of Performance Screen Supply, a Workhorse screen printing equipment distributor and a full line distributor of screen printing equipment and supplies located in Manalapan, N.J.

That is a typical dye migration issue. It’s the same as seeing pink when you print white ink on a red T-shirt. It is a result of the way the garment was dyed. One solution is to switch T-shirt brands. However, if you are printing contract, that is not possible. If you can’t switch brands, try running the shirts through the dryer at a high temperature before printing. This can cause the dye to migrate before you print with ink. Also, make sure you are not flash curing at too hot a temperature because you want to gel the ink without activating the fabric dye.

Another solution is to print a white underbase, but sometimes when you flash the white underbase you can draw the dye up into the underbase. Then this can cross link with your top layer of ink. It all comes down to using too much heat so avoid that as much as possible.

I find that the waterless hand cleaners, of which there are several, are really the best way to go. There are some that are specifically made for the screen printing industry, and others ones you can buy at an auto parts store or a supermarket. Goop is one well-known general brand. You may need to check to see if any employees have sensitive skin and then test which one is best to use. Here are some suppliers:

Franmar Chemical
309-828-2900
custserv@franmar.com
www.franmar.com
Soy Scrub Hand Cleaner Gallon No matter the size of the job or the size of the shop, hard workers generally get dirty. Soy Scrub™ makes a hard worker’s hands feel clean again by getting rid of the dirt and grime of a hard job done well. This hand cleaner is made from American grown soybeans and finely ground Missouri pumice for extra cleaning.

Chemical Consultants
951-735-5511
http://www.ccidom.com/
ProChem® HAND PRO is a heavy-duty waterless hand cleaner, containing pumice. It is designed to remove ink, grease, adhesives, and asphalt based soilers. This product is an organic based, non-toxic cleaner which is water soluble. It does not leave a sticky film after use and will not leave your hands dry or cracked.

Performance Screen Supply
800-659-8337
bob@performancescreen.com
http://www.performancescreen.com/catalog
Hand Cleaner Gentle scrubbers made of recycled plastic are soft on your skin and remove plastisol ink fast.

Texsource
888-344-4657
info@texsourceonline.com
www.texsourceonline.com
Rhino Hand Cleaner Can be used with or without water to clean ink from hands. TexMagic Hand Cleaner All natural industrial hand cleaner. Cleans the dirtiest hands like magic. Use half the soap and get twice the results.

McBee Supply

713-972-1388
800-622-3304
Mike@mcbeesupply.com
www.mcbeesupply.com
INK-OFF by Union Ink Heavy Duty Multi Surface Wipes by Sprayway

Our industry has gotten very green over the past 10 years, so there are safe chemicals to use. What you primarily need to be concerned about are your screen cleaners and that will include your emulsion remover and ink degrader.
You don’t want to put solids like plastisol into your septic system. To avoid this, scrape all the ink off of your screen and put it back in the bucket, wipe the screen down, pull off the tape and run it through your dryer. This will turn any plastisol to a solid that you can throw away as solid waste, to avoid it sgoing down the drain.
When you take that screen to the washout sink you are not going to put any plastisol ink into your septic system and the ink degrader, reclaimer, and emulsion are all available in biodegradable and septic safe formulations. Don’t assume that all are tailored to be safe, so be sure to request these products from your supply house.
By applying multiple strokes, you are doing the same thing as when you used the 110 course mesh. So it really isn’t going to solve the issue.

Make sure you get a good underbase down. The underbase gives you a printing surface to let those other colors pop from and creates a smooth printing surface. The underbase doesn’t have to be a good print, it just has to block some of that fabric. Then put your other colors on top of the underbase with a 230 mesh. Coarse mesh such as 110 should never be used in a multicolor situation unless you are printing on athletic wear.

No, it does not expire. You could have a gallon that is 20 years old, and if you mixed it up it would likely print just fine. There is no water in plastisol to evaporate and there is no solvent to flash off. Plastisol is a 100% solid product you just need to mix it up and then off you go to the races. It may be a little thicker, but it will still print.

Brought to you by, Bob Drake who is president of Performance Screen Supply a Workhorse distributor.

Yes. Metallic inks reflect the heat back toward the heater elements in an electric dryer. You need to cure metallic ink as slowly as possible. Set the dryer on the absolute slowest speed, nearly on the verge of scorching it. You may even need to run it through twice.

Of all of the metallic inks, Metallic Silver is the most difficult to print. Due to the fact that it acts like a mirror, the ink doesn’t want to accept heat. Also, 156 screen mesh is not the correct mesh for metallic inks. I recommend 83 mesh count or lower, maybe even as low as 40 or 60. A mesh count of 156 acts like a strainer, and you are not getting all the metallic flakes to push through the screen. The big particles get stuck in the mesh.

Brought to you by, Bob Drake who is president of Performance Screen Supply a Workhorse distributor.

Card or wipe as much ink as possible from the stencil to avoid that waste going down the drain. Be careful that you don’t damage the stencil by rubbing the image area. Next, rinse any residual ink from the screen with a low-pressure spray, (we use a typical garden hose nozzle). Pat the screen dry with a towel and then leave it to fully dry overnight. You can speed up the drying process by putting it in a room with a dehumidifier.

By Dan Corcoran who is co-owner ofForward Printing located in Oakland, Calif.

No because of the dyes that are used in the garment. If I took a black shirt from five different manufacturers and I printed a specific yellow, I would have five different yellows. So the only way you can get a PMS is if you are never going to change garment colors or garment brands.
By overprinting with a water-based ink, you have greater control of the color. If I discharge a garment, although it is not white, it is a light color. Now I can go with a waterbase color that is a Pantone color match (PMS).
If I change garment brands I might get a slight shift, but it will not be nearly as dramatic as if I am mixing pigment into the discharge base because I’m preventing the dyes from affecting my other colors.

SCREENS

The best type of screen is a tight one, whether it’s wood, aluminum, or a retensionable frame. Wood screens can be made tight, but they don’t stay tight. All fabrics relax over time so what you really need is a reliable method of tensioning screens.

The most important thing that is often overlooked, and a lot of suppliers don’t want to hear because it is a profit center for them, is buying pre-stretched screens. It is difficult to to buy a screen from a supply house that’s more than 20 newtons per centimeter.

By the time the screens sit in a factory in inventory, then get shipped on a truck, then sent to a dealer inventory, and then arrive in a UPS truck, they are going to be 20 newtons. That is if you are lucky, because most of the time they are going to be less then that.

If you can’t tension your own screens, you are going to be printing with soft screens and that’s the biggest mistake any screen printer can make. It makes white ink very difficult to push through the screen and it makes registration difficult.

You absolutely can. Retensionable roller frames are designed in a couple of ways. You can buy them with a square bar on the back and three rollers on the other three sides, which is designed to be used with a rear-clamping press.

They also can be used with a side-clamping press. Retensionable frame companies sell adapter blocks to go under the feet of a side-clamping press to square out the round bar. All Workhorse presses have a groove in the clamp so it can hold the round bar.

Retensionable frames are the most adjustable after the fabric has been mounted and stretched, however, they are expensive. You also need to have the right table to stretch them properly. A less-expensive option is to take a static frame that is welded and rigid and use a pneumatic stretcher.

A prestretched 20-inch by 24-inch aluminum manual press screen is between $22 and $28. You can stretch your own with an $8 screen and $2 worth of fabric and a few dollars worth of labor and glue. It’s a cheaper solution and you are assured of higher tension when you use it. If you blow one in the middle of the night or on a Saturday, you’ve got the capability to make another one. Otherwise, you might have to settle for a different mesh count that isn’t going to work as well.

First, it will depend on what kind of press you have: a rear or side clamping manual or an automatic.
One solution is to create a cardboard template with the press platen traced on it and then do measurements to determine where you place a center print, a left or right chest, a pocket, a butt print, and so on. These days there are all different types of locations you have to deal with.

Where should a left chest be located is another argument that will vary from one garment decorator to another. Some people measure down four fingers from the neck and four fingers from the center line, and they call that the center of the chest print. Some people say that is too high or not far enough left so it really depends on personal preference as well.

Without looking at the drying situation it is hard to say what is happening there. It sounds like water may be dripping from the screens above as they are drying and forming on the screen below. So one thing you might want to do to solve that problem is to put a slight incline from front to back so your water draws towards the door. This way, it drips off the surface of the screen or at least only hits the screen bar not the image.
I would say this has very little to do with the exposure time. This has to do with a couple of things. The first being that the exposure unit is probably getting hot and doesn’t have enough fans or ventilation to cool it down. That heat is making the capillary film and the film positive stick together.

The second cause is that the capillary film is not completely dry after peeling off the film’s plastic carrier sheet. It might be a good idea to stick the capillary film under the fan for a few minutes before exposing it to dry. The film positives may need a little more dry time. If you just printed them, maybe they need to sit over night before burning them.

One trick is to spray a little dry silicone on the capillary film screen before you expose it. Another trick is to lightly dust some baby powder on the film positives. Those are two things that many shops do to get them through this crisis. When you burn screens with these big powerful bulbs, they throw off a lot of heat. The glass can get so hot that the film positives melt the glass.

Brought to you by, Bob Drake who is president of Performance Screen Supply a Workhorse distributor.

This problem may be caused by your exposure time not being long enough, but more then likely you need to look at your film positive. When you hold your film positive up to the light, it should be totally black. Are your halftone dots the proper size? The rule of thumb is to take the mesh count and divided it by 5. That is what your screen count should be. So if you want to print on a 110 mesh screen, 110 divided by 5 is a 22 line print halftone.

Bob Drake, president, Performance Screen Supply, Workhorse distributor

From what it sounds like there are two things that may not be right. It’s either the press or the screen that is causing this problem. My inclination is that it is the screen. Chances are that the tension is low and so when you come back a second time, you are getting a blur. Try to use higher tension and see if that does not solve the problem.

Sometimes people buy a prestretched screen and they are told it is tight. Don’t take their word for it. Measure the tension. Tension is a huge factor in keeping design clarity and maintaining productivity.

The question doesn’t specify if the printing is being done on light or dark shirts, which also makes a difference. On a light shirt, you can go up to a mesh count of 280 or 305. However, this can be overkill if your design doesn’t have enough detail in it to benefit from the finer mesh count. And, you can be making life more difficult for yourself if you don’t need a higher mesh counts, because they can be more difficult to print with.
My favorite mesh is a 230 and I can take that up to 36 N/cm of tension without any trouble. It always gives me beautiful clarity and a nice ink lay down.

If you’re printing on a dark color, then you need to go to a little bit coarser mesh, like a 156. However, with darker shirts the squeegee comes more heavily into play. I recommend a 55/90/55 squeegee. This will give an excellent lay down of ink.

ART

Epson and all inkjet printers are designed to print color, they are not designed to print black on clear. You always have to add a piece of software in the middle called a raster image processor or RIP. Because there are so many printers on the market and they change all of the time, you need to make sure you buy a RIP that is compatible with your printer.  Some suppliers:

Performance Screen Supply
800-659-8337
bob@performancescreen.com
www.buyarip.com
A free trial is available for AccuRIP, which is designed for printing direct-to-film positives for Epson printers features a 14-day trial offer.

Wasatch Computer Technology
801-575-8043
800-894-1544
wct@wasatch.com
http://www.wasatch.com/

T-Biz Network International
480-212-1078
888-801-1561
info@tbiznetwork.com
http://t-biznetwork.com/t-seps/t-rip-software/

McBee Supply
713-972-1388
800-622-3304
Mike@mcbeesupply.com
www.mcbeesupply.com
We carry ACCURIP, which is great system. It’s very friendly and haws great customer service and tech support company.
Here’s an online article about RIPs by Terry Combs. http://t-biznetwork.com/computergraphics/the-confusion-over-rip-software/

If you don’t have the money, one way to fix this problem is to print two film positives and tape them back to back to try and get them blacker. The right way is to get raster image processor (better known as RIP) software and use a printer like an Epson 1400 and special black ink. That prints super black. The ink should be a UV blocking dye-based ink specifically designed for printing film positives.

Bob Drake, president, Performance Screen Supply, Workhorse distributor

There are a lot of industry-specific screen printing separation programs. Most veterans are going to be a bit biased on the best program. Obviously, PhotoShop is the industry standard, but it is not a separation program. You have to learn so much about it that it can be challenging for non-artists or anyone who is not a regular user of the program.

Other separation software programs on the market are Photoshop plug-ins, which means they have automated the steps for you, but it is still PhotoShop. I have been using a program called Separation Studio. It has tools similar to PhotoShop, but it is a stand-alone program, not a plug in. It comes as close as 90% to what your print is going to look like.

There’s a trial version you can download and play with for a couple of weeks. Whatever software you are considering, you want to be able to download it and test it. Make sure to choose one that works best for you.

Make your life really easy and use a 61 degree angle for everything. I use a 45 lpi 61 degree angle with a 230 mesh. It’s fine if you want to get more complex, you can definitely go higher in terms of lpi. But unless you want to spend time playing with it, I consistently get great results with a 230 mesh at about 35 neutons.