What is Screenprinting?

lost love show printshop

You can print shirts, patches, posters!

You can print on paper, wood and fabric!

And we are happy to help you!

Here is some more detailed information on the wonderful world of screenprinting

What you need for SHOOTING SCREENS This is HOW you get your image onto the screen.
an acetate of the image to be printed  or a xeroxed piece of paper (more details below)
a screen stretched on a frame
emulsion
an emulsion scoopcoater
a light source  (in our case an exposure unit with vacuum)
a dark room
running water

PRINTING
ink
a squeegee
tape
paper, fabric, or T-shirts

What is an acetate?

Your acetate is the image of the art to be printed photocopied onto a clear sheet of plastic (acetate). You need your artwork transferred to an acetate to accomplish the first step: shooting your screen. It can be done at Kinko’s or any other copy shop. Just ask them to photocopy your image onto an acetate. The darker the toner on the acetate the better your image will reproduce when printing. If there are tiny pinholes you should ink them in with a felt tipped marker. Sometimes jobs get botched; get two acetates done. That way you can put one on top of the other and your image will be very dense.

You will need one acetate per color you plan to print, as one screen must be shot for each color. If it’s your first project though, we recommend starting simple and going with one color.

I’m confused: what, on the acetate, actually gets printed? 
Whatever is black on your acetate, tracing paper or inkjet printed paper will get printed.

What if I have gradients of one color?
How will this affect the screen?

That depends a lot on the image itself; you might want to tweak photographs or other gray-scale images on a computer, get it really sharp, erase any little doodads or artifacts which will show up on the screen. Generally, gradations or gray-scale images come out just fine, but if there is a lot of subtlety involved, make sure you get the right kind of mesh for your screen. You can discuss this with a PrintShop volunteer either at a Wednesday meeting, or by contacting us through our website with a written question.

What else could I use to expose the screen other than acetate?

The other way to transfer your image onto the screen is using a Xeroxed piece of paper. It will not work if the paper has been printed off a computer printer. Places like Kinko’s in the CBD are perfect for this… and they know us well, so some of the employees may be able to help you. When you are photocopying your image make sure you adjust the density to one of the darker settings. If you have lots of gray dots appearing in your print you can adjust the settings to increase contrast (if the dots are too strong they will show up in your final print). Please bring several versions of your image with you, then we can pick the best one to use. Once you get to the shop just grab a rag and carefully oil your piece of paper, front and back. It should start to look slightly transparent… this means its ready!

What kind of Ink should I use?

We only use water-based Ink at the New Orleans Community Printshop. Please do not bring any oil based (plasticol) or other soy based Inks into our shop, we do not have the right materials to clean up after these inks and the screens will be ruined! All of our water-based inks have longevity on fabric: oil tends to break and crack after years of being tossed in the dryer, and water-based gently fades. The longevity of a printed shirt has more to do with the QUALITY of the cloth and ink, and how much care you put into printing rather than the TYPE of ink. We choose to only allow water-based ink because the ink is relatively non-toxic and does not require solvents for clean up.

How do I prepare a screen for shooting? 
We will do this for you at all Open shops, and our Members prepare the screens before you even get there!

Of course, we will also gladly explain how this works, it’s much easier to explain if you’re there to see the materials.

How long can a screen covered with emulsion last before I shoot it?

We sometimes leave screens for a week at the shop. However, any screens left at the shop, after an open night cannot be claimed later unless by special arrangement. We have a limited amount of screens, so please don’t count on saving multiple screens for later open nights.

How do I shoot a screen? 
Again, this is something much easier to explain in person. We’ll help you. Take notes.

A few pointers though: 
clean the glass surface on the light table.
tape the acetate to the glass and place the screen flat to the acetate
turn on the vacuum and light and expose your screen (always ask a Printshop Member to help). Exposure times vary. We have times listed in the exposure room.
after exposure quickly rinse off the emulsion completely on both sides of the screen with cold water
let the screen dry, then tape up the edges

How do I print the image?
Again, come watch us and take notes. We’re here to show you how. A very good piece of advice is to have someone with you when you are printing, so that one person with clean hands can lift the shirt or paper off the table and place down a new one. The other person will be running the squeegee over the screen and spooning the ink onto it, so their hands could be too messy to touch the shirts or prints, though having someone with you is not required if you just take care. Do a few test runs on paper or bits of cloth first to get the hang of it.

What if I do a test run and there are places where the ink shouldn’t come through?
This can happen. If you hold your screen up to the light before doing a test run, you might discover one or two tiny pinholes where light is coming through the screen, and hence, where ink will come through the screen, usually in places where you don’t want it to. If the holes are really small, you can daub them with screen filler. If the holes are slightly bigger, it’s possible to use some packing tape on the side of the screen opposite the one you run the squeegee over.

What if I get a dab of ink on the shirt? 
If you’re using water-based ink try a dab of water, or wait until it dries and paint over it with a brush.

Remember, no matter what you do, you’ll probably ending up messing up a few t-shirts or prints. It happens. Calm, quiet focus helps, and an ability to forgive yourself for messing up. (Again, having a few crappy test-shirts helps!) Anyway, its a handmade print… sometimes a little mess adds character.

What is a squeegee?
Look in the sink or on the wall and you will see apiece of wood w/ a rubber insert; that’s what you use to push your ink through the screen in strong, even strokes.

How long does the whole process take?
Well, it depends. If you’re screening one-color, one-sided t-shirts and you have the ink you want, a pre-stretched screen, serenity, patience, humor and determination, you can print your (say) 25 shirts and have them dry and walk out in an hour and a half. I would add on another 2 hours for putting together and shooting the screen. But, I have also seen many people mess up and take weeks to finish their projects, which is OK: you have to learn, and sometimes you have to make mistakes to learn.

It is most enjoyable to silkscreen when you have plenty of time. That way you can muse over your image, carefully shoot your screen and have time to mix the perfect colors before you start to print. Depending on the scale of your project do not be surprised if it takes more than one open shop night to complete it. I see people making the most mistakes when they try to get it all done AT ONCE; they get very stressed and tired and wear themselves out. Plan ahead and pace yourself. We cannot stress this enough. In fact, PLEASE, re-read that last sentence! Take your time and do the job right. Don’t wait until the last minute. The Printshop can be a very busy place, and volunteers have limited time!

How do I clean up?
For us, this is the MOST IMPORTANT part of the whole thing. If you don’t clean up your mess, we hear about it from everyone else.

When washing water-based ink from your screens use high-pressure water on both sides of the screen until all the ink is thoroughly washed out. If you don’t get all the ink out it will dry in the holes in your screen and new ink won’t pass through. It is important to rinse water-based screens as soon as you are done with them. Also, pay close attention to the spaces where the screen meets the frame. Often Ink gets trapped and then runs down later as an unwitnessed villain after the screen is set aside to dry.

Recap the inks you used as well as any rags, and generally tidy the place. Wash out your squeegees. You will find that water-based ink vanishes quickly under water, and is therefore easier to clean up. Please take to time to double check the space you used… did you wipe down the acetate you used for registration? Did you remember the image you brought to burn? Are there wet pieces of paper in your area? IF YOU LEAVE YOUR SPACE CLEANER THAN WHEN YOU GOT THERE WE WILL LOVE YOU FOREVER!

IF YOU BROUGHT YOUR OWN SCREEN DO NOT LEAVE IT AT THE SHOP! TAKE IT HOME WITH YOU. Screens left at the New Orleans Community Printshop may be damaged, destroyed, thrown-out, or used for another project.

We hope these Tricks ‘n Tips have been helpful. We look forward to helping you with your project, and then, in turn, seeing you help others.


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