#screen printing tutorial

Photoshop for Screen Printing

Depends! Determining your exposure time comes down to two factors - the type of emulsion you’re using, and the mesh count of your screen. One way to find out is to use our free exposure calculator (get it here). Print it out on a transparency, and burn it on your screen. While burning, block all rows except one with an opaque paper. Follow the directions provided to calculate your correct time, but the idea is that as you move the paper down, each row will have a different burn time. Wash the screen out, and the row that washes out best will give you your burn time!

Elbow deep in ink and can't figure something out? Don't rip your head through your screen just yet - we're here to help. This here Tumblr now has a sweet ask feature, so next time you're considering using your squeegee as a baseball bat, be sure to ask. We got your back.

(I'm going to publish this since it may be useful to other people who are interested in the process, if that's not okay let me know and I'll take it down.)

First off, good for you! Screen printing can be very challenging, but also incredibly rewarding in a way that is very unique to the process. Let me go ahead and answer your questions as best I can = )

Exposure - For this I use a home-made light box, I made it years ago when I first started because purchased lightbox units specifically for screenprinting are in the $1,000+ range, and I made mine for probably $50-$80, with wood and glass. Whatever screen you are planning on using, get a piece of glass that's a few inches bigger on each side, build a box that's a little smaller out of around 6" tall pieces of wood, drill holes in one side for the electrical cords and voila, light box! The screens we use are 20"x24", so my lightbox is around 25"x30". The distance from the lights to the screen is important, you want the light exposure to be as uniform as possible- so you want the screen to be around 6-8 inches away from the bulbs. For bulbs I use strip lights, flourescent tubes, 6 arranged in a row from one side of the box to the other, for the best and most even light exposure. There are a lot of great but sometimes conflicting tutorials on this subject matter and honestly, I think any light will work, it's all about finding your exposure time.

Talking about exposure time - Find some image online or make your own to use as an exposure sheet. You find your exposure time by putting this transparency on a screen and using a thick, thick paper to cover up most of it, expose for 1 minute, then move it down, expose for 2 minutes, etc. Until you've done this around 10 times. Then you wash out the screen and see what came out the best. This is the most frustrating part at times, because there are SO MANY things that can effect your exposure time. The emulsion you use is a huge part of it, but if it rained yesterday it will change a little, if your coating isn't the same every time, having a thicker or thinner coat of emulsion (Make sure you use a scoop coater, best purchase I ever made!) can make a huge difference. 

Wash out - This is another one that took me a while to learn. It's best to use a hose sprayer on a light soak setting, not jet, for the first bit of washing out. I spray down both sides, count to 20-30 in my head, and continue to wet both sides until I start to see the emulsion coming out. Once I see the emulsion coming out, I start to spray it a little more aggressively, but always be careful to not continue spraying it. The emulsion might be exposed, but it's not so hard that an aggressive spray of water won't blast out fine detail work. When you think you've got it all, hold it up to the sky so that you can see everything. Examine each corner, every nook and cranny, because you have probably missed something that the light will show you! If you take too long to wash it out, the hardened emulsion will get weak and fall off, and then your screen is ruined and you have to start over, so it's a bit of a timing game. You don't want to do it too fast/aggressively, or too slow.

Chemicals - We use eco-friendly inks and emulsions, but we use a screen to filter the washout basin water to make sure no chunks go down the drain, and we throw away what the filter catches in the trash. The reason we're able to use water-based, eco friendly inks is that we're a smaller company and we do a print run all at once. With more toxic plastisol inks you can leave the screen and walk away and have lunch; with water based if you stop, the ink will dry in the screen and ruin it if you leave it for more than a minute. It's another challenge, but the water based inks are worth it in my opinion for the effect you get. Plastisol is a thick plastic like substance that sits 'on top' of a shirt, whereas waterbased inks are much more like a dye that soak into the fabric and are much less noticeable to the touch, which is a great plus in my opinion. 

Squeegee- We buy these from Ryonet, but they last a long time for us and they only cost around 12-14 bucks, so for me it's worth it just to buy them. I know you can replace the rubber, I believe that they sell the rubber, but I'm not sure I'd be able to replace that as I've never tried! We buy most of our screenprinting supplies from an American based company Ryonet, they have truly been a one-stop shop for our supplies and their prices on MOST things are pretty fair!