SCREEN PRINTING & DIGITAL | SUPPLIES, EQUIPMENT & SERVICE

What mesh should I use?

There's a right and a wrong mesh for every job. The ink, artwork and impression you want to leave with your print are the major deciding factors. Some special effects glitter inks, for example, require a 25 - 40 mesh count for the particles to pass through. For good opacity on dark t-shirts, 85 - 110 mesh is recommended. Finer artwork, or darker inks on light shirts 156 is standard (when hand printing). Poster printing, process work and conventional inks, use mesh ranging from 195 - 355+. If you have questions about your specific job, feel free to Contact Us.

Coating a Screen.

A properly coated screen will solve a number of exposure and printing problems. These steps should help guide you to better coating your screens.

1. Coat the printing side of the screen first. Use a medium to quick stroke from the bottom up.
2. Turn the screen so you can coat the squeegee side, but also turn the screen so that if you coated from top-to-bottom you will now be coating bottom-to-top.
   • *2.a. Add yet another coat to the squeegee side of the screen to make for a sharper and heavier ink deposit once the screen is burned.
3. Then, let the emulsion fully dry, horizontally, print side down (on a rack, etc).

My image won't wash out.

The most common problem with screen burning is under-exposure so it is rarly the case that washout problems are due to the screen being in the exposure unit for too long. More likely, the emulsion on the screen was not completely dry, the positive artwork isn't solid black enought to block light, or the film positive does not have enough compression to the screen during exposure. Another trick for washing out the stencil is to quickly rinse the screen immediately after exposure, and then coming back after a minute to blast out the screen with high pressure. This gives the water time to soften the un-exposed areas before you blow out the image.

My stencil (screen image) is falling out.

Your screen is likely under-exposed. Use a step-wedge test, or exposure calculator to determine the best exposure time for your set up. If necessary, replace the bulbs in your exposure unit. (A typical exposure time should be in the range of 7-15 minutes.) Then, be sure that you have good compression (either by even weight or vacuum) between your positive and screen. Lastly, after you have washed out your screen, post-exposing (placing the screen back on the exposure unit) can help lock in the image for better long-term durability.

White ink problems.

Printing white ink is still a stumbling block for many t-shirt and apparel printers. While white ink technology has come a long way, there are still some factors to consider that will make it much easier to print white ink with great opacity and durability.

1. Mesh. Using an 60-85 mesh screen will allow more ink to pass through the screen, giving better coverage. You may lose detail in your print with 85 mesh, but it is a trade off to consider. With improved technique, you should be able to use a 110 or even 156 mesh screen to print white.
2. Emulsion Thickness. Having a good coat on your screen, using multiple passes on the front and back side, will increase the thickness of the deposit of ink that you can lay down in one pass. See the Coating a Screen question (above) for more details.
3. Off-Contact. You need to have a 1/8th inch gap between the screen and the substrate. See the Off-Contact question below.
4. Squeegee/Technique. Lastly, it comes down to the printer. If you have considered all of the factors above, and you have a straight/sharp squeegee, a good pull (or two) is all it should take to produce a great white print. Be sure that your squeegee angle is more upright, more than 45 degress. Many printers tend to push ink through at a 45 degree (or less) angle. Your squeegee pressure should be strong, but not so much that you really bend the blade. Also, your squeegee speed should be fairly quick. If you can see that not all of your ink printed down to the substrate, make another quick pull.

What is off-contact?

Off-contact is the term used to describe the space between the frame and the print surface. The common measurement for off-contact is about an 1/8th of an inch, or "about the thickness of a nickle". (Many printers will physically tape a nickle to the underside of the frame to guarantee this.) Having the correct amount of off-contact ensures that the screen will release from the print after a squeegee stroke and that all of the ink that was loaded into the stencil with the flood coat will cleanly release to the substrate.

What is a squeegee's durometer?

The durometer of a squeegee is the relative softness or hardness of the rubber blade material. The typical squeegee durometer range is from 60 duro, which is considered a soft squeegee to 90, which is considered hard. Generally speaking, softer squeegees will push more ink through a screen (better opacity), and harder squeegees will leave a lighter deposit (better detail).

Another factor to consider is the sharpness of a squeegee. Sharp squeegees will also lend themselves better to higher detailed prints, where dull/old squeegees will preform will less consistency. You can have a squeegee sharpened when it goes dull, and even buy beveled or round-nose squeegees to perform a specific job.

What's a RIP?

A RIP (Raster Image Processor) is a piece of software that converts postscript information from your artwork creation software (Photoshop, Corel, Illustrator) into crisp halftones, and/or opaque solid areas that can be used to expose screens when printed through a standard ink jet printer, and onto inkjet positive film.

How do I use Lancer's 801 Foil Proof? (video answer)