Learning to Screen Print!

Over the past few weeks, we’ve been learning how to screen print here at the Ellijay Makerspace. We’ve had some ups and downs in the process for sure, but we’ve learned a lot and we get better at each new project/design.

The first thing you’ll need to work through as a beginner is getting just the right thickness of emulsion applied to the screens. Be sure to de-grease them first, even if you have brand new out of the pack screens. I didn’t think it would matter, I was totally wrong. You get big clumps of emulsion sticking together and an unusable screen. So de-grease thoroughly and let it dry completely before you apply the emulsion.

We used AP Blue EcoTex emulsion. I did two pulls on each side of the screen, the first using the applicator to apply a thin layer to the screen, and a second pull to clear any excess emulsion off the screen. The first pull is at a lower angle, allowing the emulsion to flow to the edge of the applicator before pulling, and the second pull is at a higher angle, using the edge to pull excess emulsion off. Do this on both sides, and do this under a red light like you would use for photo development, as UV light will cause exposure and ruin your screen.

I had to learn the hard way that you will still have some transparency when holding the screen with emulsion up to the red light. It may look too thin or slightly blotchy when you look directly at it, so don’t use this as your test. Instead, tilt the screen so you’re looking across the surface of the screen at an angle. This is the best way to see what the surface of your screen actually looks like. While still wet, it will be an even, shiny surface. Make sure it looks clean at this angle before putting the screen somewhere dark to dry. We use one of our hall closets for drying, with a note on the door warning folks not to open. Anywhere reliably dark will work. The screens will dry in 4-6 hours depending on humidity, but I like to let them dry overnight rather than having to try and guess if its fully dry yet.

The next step is to go ahead and get your screen design ready. Convert images to black before printing, including all layers of a multi-colored design. Then print in black ink on a transparency.

A two layer screen we printed

Once the emulsion on your screen is dry, you should take your transparency into your darkroom and tape the transparency to the screen using clear tape. For a single color design, the focus should be on getting the design centered and even in the frame. If its off its axis, it will be difficult to get good alignment when laying down shirts to print. Put the transparency face down on the flat side of the screen (you should be able to read it from the deep side, as this is where the ink will be applied). Then use a black trash bag to move your screen to where you’ll be exposing it.

There are a number of ways to expose, but I have only figured out the one we have at our disposal. We have a UV exposure unit that works really fast. Our exposures only take 15-20 seconds, with the more complex and detailed designs being closer to 20 seconds. You’ll probably need to experiment with the length of exposure depending on the type of emulsion you use. Our emulsion bottle said 7-12 seconds on the label but that was too short for our machine apparently. Be sure to put the flat side of the screen face down on the machine and cover the transparency with a dark fabric on the deep side, and apply as much pressure as possible. This will help you avoid ending up with soft edges on your design, from the light bouncing back from the other side.

As soon as you have finished exposing, get your screen to a sink with a good hose as soon as possible to wash out the unexposed portions of the image. We use a garden hose with multiple settings, and I tend to use the flat/jet settings to blow out the unexposed sections, and then the shower setting to rinse down after I can see clearly through the design (emulsion will get stuck to the sides of the screen if you don’t rinse thoroughly enough, but you only want to use high pressure until the design is clearly visible; excess pressure can begin to rip the details of your design).

Using the jet setting to wash out a screen

Once you’re able to see your image clearly without any speckles (hold it up to the light and look closely in the blank spaces, and continue hitting any speckles until they are removed), you can lay it out to dry. Make sure its completely dry before trying to apply any ink. I let them sit for about an hour and give them a wipe down before taking them to the carousel.

Next, we lock the frame into the carousel. You may need to do this freehand, which is harder to align but you’d be fine. The carousel is great cause it allows you to align multiple screens for a multi colored print. Spin the knobs till they lock the base of the screen into place.

Locking a screen into the carousel

Then you lay out your shirt (if this is the first time using this particular screen, use paper for the first two or three pulls, as it often comes through kind of thin the first few times). Then you’re gonna “flood” the screen with ink; apply some ink to the area around the design, then very lightly drag your squeegee across the screen to spread the ink across the design. You don’t want to apply any pressure here, you just wanna cover all the transparent parts of the design in ink.

Flooding a screen

Then you apply pressure evenly and pull the squeegee across to push the ink through into the fabric!

Squeegeeing

If you’re going to make multiple shirts at once, be sure to scrape the ink off the squeegee after each pull so you can keep recycling the ink you’ve already taken out of the jar. Get as many pulls as you can at once to minimize wasted ink from transferring out of and back into the container.

Then your final step is to use the heat press to set the ink into the fabric. The ink we use is heat-setting and must be warmed up to actually remain attached to the fabric.

Fresh off the heat press

And just like that, you’ve got your own homemade custom t-shirt! Come by the Ellijay Makerspace and sign-up as a member and we can get you started making your own shirts today!

And check out our Screen Printing Shop if you want to buy one of our custom designs!

-Connor

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