The Perfect Laughter Guide to Screen Printing Problems

Learning to screen print can really pay off, but it’s pretty intimidating to try it. There are so many ways something can go wrong, it’s really difficult for rookies to get decent results. It’s no wonder than many people who like the screen printed aesthetic go the Gocco route. But with supplies getting scarcer and more expensive, it’s worth it to learn regular old screen printing.

As you can see from these photos, we don’t have any fancy equipment. We’ve never bought any kind of beginner “kit”, only screens, emulsion, and transparencies from Kinkos. Our screen is sitting on a black t-shirt and our hardware store light is supported by a board, a washing machine and a ladder. Our “press” is just a large board with some screen printing specific hinges (Available at Dick Blick) screwed to it. The real investment we made is was the time we spent getting it to work!

We wrote this guide to help people avoid some of the frustration that we experienced when we screen printed our wedding invitations. It’s not a beginner’s guide – it assumes that you’ve researched the basic process, tried it yourself and need help troubleshooting. (If you’re a beginner, the Gigposter forums are a great place to start.)

Our complete guide is behind the cut. We hope we can improve it over time, so please comment with any suggestions!

I’ve tried some of the basic all in one kits for screenprinting What would you suggest the best kind of supplies have you had the most success with?

We first began using the Speedball Diazo screenprinting kit, with some success. The upside of this kit is that is all inclusive, relatively inexpensive, and readily available at most art supply stores. On the downside: the emulsion must be mixed prior to using, it doesn’t allow for as fine of detail as other emulsions out there, and it can be difficult to reclaim the screens after use. We have since switched to Ulano QTX emulsion and remover and have not looked back. While slightly more expensive ($30 a quart) , it comes premixed, exposes in a short amount of time, and reclaims wonderfully. Also, we have had the most success with screens produced by Lawson Screen and Digital Products. We are currently using their 160 mesh count screens and find that they work well with both vector based, and halftone printing applications, and are about the same price as other (and in our experience, lower quality screens produced by Speedball and Blick art materials). The ink we use is Speedball Acrylic ink. The ink permanent and available in many colors. A word of caution: we did have trouble with Speedball’s Water Soluble ink. The Water Soluble ink, while I’m sure is great great for use in schools where easy cleanup is a must, did not dry evenly or quickly for us. Also due to the fact that it is water soluble the ink can easily smudge even months after printed. For those of you in the Metro Detroit area, we have found that the best sources for the Ulano emulsion, squeegees, and other equipment is Blick Art Supplies in Dearborn, and for Speedball Acrylic ink, we go to Utrecht Art Supply in Detroit.

After exposing, the emulsion won’t wash out where it’s supposed to. Parts of the design didn’t burn.

Make sure your positive is opaque enough. We use two transparencies taped together. They must match each other exactly. Double-sided tape is your best friend for this part.

EDIT: We’ve ‘sperimented with using only one transparency. One seems to work fine when we use a fast exposing emulsion (< 10 minutes). Two is usually needed if your exposure time is longer.

Also, make sure your screen has been drying in the dark before you expose it. You’d think this was a no-brainer, but we fell victims to a closet door that was letting a sliver of light through.

After exposing, my emulsion is washing out where it’s not supposed to. I’m losing fine detail.

If you’ve used the screen before, you have to use a degreaser before coating it with emulsion. No fancy chemicals are needed, just wash your screen with dish soap after removing any old emulsion. Otherwise, a film will form on the screen and the new emulsion won’t adhere well.

If that’s not the problem, make sure your positive is being held down completely flush to the screen. We had been using a clear piece of plastic or plexiglass, but it wasn’t heavy enough. Thrift store picture frames are cheap sources for big pieces of glass. Also, try to find exposure times for your specific emulsion online, times can range from 30 seconds to 15 minutes depending on the brand of emulsion you choose.

Also, we originally set the screen directly onto of the dark fabic that we placed under the screen while exposing, this caused the heat put off by the light to build up on the underside the screen and effectivly bake the emulsion. This led to great difficulty washing out the screen after exposure. We now place empty paint jars under the four corners of the screen to allow the heat to dissipate.

My screen is burning fine in the middle, but the emulsion is washing out around the edges.

Your light is coming down from its source in a cone shape. If the light is too close to your screen, the entire design won’t be inside the cone of light. Move your light source away from your screen. You may need to lengthen your exposure time after you do this.

My prints are faint and/or there are some spots where the ink isn’t pushing through onto the paper. (This is where we had the most trouble. Alternative solutions welcome!)

EDIT: We just found out that spraying water mixed with a little bit of dish soap on the underside of the screen before you put any ink on it helps a lot!

For some reason, our screens were getting clogged in certain spots. This mostly happened at the beginning of each run. We rubbed the trouble spots on the underside of the screen (closest to the paper) with a wet cloth. We used a lot of pressure when we did this, and it cleared out.

Because we were having this problem, we did a LOT of test prints on scrap paper before beginning to print on the good stuff. After about 5-10 test prints, sometimes more, the ink was flowing through the screen pretty well and we had identified and fixed our trouble spots. But this process was pretty frustrating and took up a lot of time.

More advice: work fast once you start printing. If a screen full of ink is left idle, the ink will start to dry inside of the holes. If you do have to stop for a minute, flood it to provide a “blanket” of ink to protect the holes from air. Also, make sure your inks are closed tightly in storage so they don’t thicken. Also, adding a bit of transparency extender will prolong the drying time of the ink, reducing the likelyhood of ink drying in the screen.

My prints aren’t sharp. It looks like too much ink is getting globbed on the paper.

At first, I thought I was holding the squeegee wrong or applying the wrong amount of pressure. However, it actually has to do with the amount of ink that’s already sitting in the holes of the screen. After pulling a few prints, especially if you flood it after every one, excess ink may begin to collect on the underside of the screen. The only way we could fix it was by wiping off the screen (the side closest to the paper) with a damp cloth. After each print, make sure the ink isn’t going on too heavy, and if it is, pull a few prints without doing a flood stroke.

Halftone dots are are totally cool! What do I need to successfully produce halftone prints?

It was a bit of a challenge for us to successfully burn a screen with halftone dots. Using this tutorial, with a little tweaking, we able to prepare a file to be printed on transparency. I output the file at 300 dpi, and set the halftone frequency to 40 lines per inch and at a 53 degree angle. A good rule of thumb is to set the lines per inch to 1/4 your mesh count. Since we were using 160 mesh screens, we used 40 lpi. I also chose the 53 degree angle for the halftone to avoid an inadvertent moire pattern from forming. Finally, due to the fine dot pattern we attempted to burn we used scotch tape to hold down the corners of the transparency.

I can’t reclaim my screen after printing. The emulsion won’t wash out.

EDIT: We realized that much of the problems we with reclaiming our screen had to do with us using a garden hose to reclaim it. What we have been doing recently, with much success, was taking the screens to the self-serve car wash and using the powerwasher there to reclaim he screen. This works perfectly and only costs a couple of dollars per use. One could also look for a used power washer on Craigslist.

Assuming you don’t have a dark room with a fancy drying unit, how long did you let the emulsion dry after you coated the screen? If you exposed a screen without letting it dry completely, the emulsion could have fused to the screen. Cue sad trombones; it’s never coming out. Next time wait at least 24 hours before exposing, or more if the weather is hot or humid.

4 Comments on “The Perfect Laughter Guide to Screen Printing Problems”

• Designing Our Wedding, Part 1: Invitations — Perfect Laughter
  

  [...] every problem you could possibly have six ways to Sunday (all of which are documented in our handy Guide to Screen Printing Problems). In the end, we were very happy with the quality. Running our fingers over the dry ink was so [...]

  09-21-09 » 8:43 AM »

• Brent B
  

  Finding good guides to screen printing, going beyond the simple steps to start, has been quite the search. Awesome tips, thanks so much! I’ve been using my bathtub for washing out and reclaiming my screens, and well, that works horribly. I never thought to use a car wash pressure washer. Genius!

  04-16-10 » 10:51 AM »

• Debb
  

  Thanks for sharing, I’m venturing back into screenprinting after a long hiatus since art class of high school. These pointers are very helpful.

  04-16-10 » 12:32 PM »

• weekends are the best things ever. « Little Me, Big You.
  

  [...] And solutions to screenprinting problems. You even could say it’s all about troubleshooting so…. [...]

  04-23-10 » 9:13 AM »

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