Screen Printing: Cheap, Dirty, and At Home

Step 3: Spread the Photo Emulsion onto the Screen

This is where all those scraps of cardboard come in handy. The backs of old notebooks work particularly well.

Read the instructions on the emulsion and activator bottles and follow them carefully to mix them together properly. Pour a little bit of the emulsion onto the screen and spread it as evenly as possible onto the screen. You have to coat both sides. You can scoop the excess back into the pot of emulsion. Don't put it on too thick. You need a thin coat, as even as possible, and on both sides. Try to avoid drips. Again, you don't have to be a perfectionist. Just do your best.

Once you've got the emulsion on there, put the screen in a darkish place to dry. Closets work pretty well. It doesn't have to be totally dark like a photo lab or anything. I like to point a fan at the screen to help it dry faster.

Once it's dry you're going to want to go straight on to the next step so that the emulsion doesn't get exposed and harden completely on your screen. You can touch the screen to feel if it is dry.

Comments

[beebek]

Didnt found the emulsion like "Diazo Photo Emulsion". But found some kinda orange crystalline material. The shopkeeper told me that it is the stuff that screenprinter guyz asks for. But the shopkeeper guy dont know which chemical to mix the crystalline material with to prepare the emulsion. Dont wanna mess myself with mixing the chemicals....
Can somebody please post what kind of chemicals are used for making the photo emulsion !!

[beebek]

Yesterday I found out that the crystalline material was dichromate. Now what another chemical to mix with the dichromate....any Idea...??

[murtaza121]

miss tracy i have one little problem we dont have emulsion in our country and its very expensive to import things rather we have some thing called alco (I hope i am spelling it right) and the sensitizer. the alco is a white paste (like white glue) the sensitizer an orangish sort of liquid. is it the same thing that u have described here ?

[mirabid]

sa murtuza.. if u ur living in karachi pakistan then i can suggest u some places for all the material...

[murtaza121]

yeah tht wud be awsum where is it?

[almateus]

it may be interesting to know that the "emulsion" is white glue with a dye (that´s why it may be green or blue) and the sensitizer is potassium dichromate (wash your hands after using, toxic). It is the same process as in the old photographic method with dichromate and gum, but it uses the glue to close the screen.

[lindamermaid]

What ratio of glue to sensitizer works best?

[almateus]

they say to use 9 parts of glue to 1 of the sensitizer. I have never determined the concentration of the dichromate in the sensitizer, but if you use the store bought solution, that is the ratio.

[tnydul]

The emulsion is just regular white glue with dye? and the sensitizer is just a potassium dichromate solution? Is there anything else to this? It seems like this should be easy enough to make on my own. Luckily I'm a chemistry teacher so I have the ability to order K2Cr2O7 easily enough.

[lbotalon]

i dont know how this guys were talking about.. can you explain to me what is the emulsion and its use,, and the synthesizer???

[lcherry]

do you have to mix the potassium dichromate with water? also, what kind of glue do you use?

[almateus]

the glue is just regular white glue. You can prepare a solution of the dichromate in water. Since the glue is water based, you can mix it with the dichromate solution.

[almateus]

yes! I am a chemistry teacher too. I have done it with white glue and dichromate many times. The dichromate crosslinks the polymeric chains of the glue, making it insoluble. Cool project to work with the students, and they get to choose the design they want to put on the t-shirt.

[lbrownlee]

I have just put my emulsion on my screens but that was like 2 hours ago and they are nowhere near dry! How long should they take! Help!

[sbryer10]

i just made my own screen using this method and its turned out well but from reading some comments im wondering wil this really turn out well? plus is it realy nesessary to coat the screen with emulsion both sides

[BrandedScreenPrinting]

You may be able to get away with only coating one side of the screen for short runs of shirts or with black ink, but the the stencil thickness is important for using white ink, thicker ink or for longer runs of shirts. When it comes down to it, the emulsion is only an extra couple cents to coat the other side, so you are really not gaining anything by not coating both sides. We use the round side of the scoop coater for printing on low mesh screens and for using thicker inks and the sharp side for higher mesh (195 and above) or for black and thin inks.

[Hal Newcome]

I must have used too much goo because my screen took a long time to dry. It stayed sticky for over an hour, until I pointed a fan at it. So, definitely use a fan. I also had some drips form that were harder to get rinsed out of my design. Everything worked out well in the end, though. Thanks for the instructions!

[labo]

how to print with different colors?

[tmillet]

1. Do all necessary steps until you get to the point where you have an image in your screen. 2. On the flat side of your screen (The side that will be placed on the shirt or whatever you are printing on) put tape on all parts of the image that you don't want printed yet. 3. Print your first color. 4. Wash the ink out of your screen and remove tape. 5. Now tape the places that you just printed. 6. Choose a second color and print it. Now, using this pocess you will have to guesstimate where to line it up, so it can be hard with a complicated image.

[garageprinter]

In answer to both of your questions - to print different colors you will have to use a new screen for each color and with this simple process you will have to align the design by eye. You should let each color dry before printing another color or you will pick up ink on the bottom of your screens. This technique is fine for designs that don't require exact registration. There are several sensitizers to mix with emulsion - you should use the sensitizer recommended by the manufacturer. You can also buy presensitized emulsion - by far the easiest way.

[ravenprints]

(removed by author or community request)

[garageprinter]

I've been printing since 1995 and have a 6-color manual press with micro-registration, so I know a bit about the process. I think that for the home hobbyist, registration would be a little tricky. I'd like to see your micro tuner though, it sounds great!

[ravenprints]

I have used every brand of that style of press. Due to my micro-tuners I can get BETTER registration and more consistent, on a press that fits on my kitchen countertop. It is all due to the on-screen registration. Rotary presses lose some registration efficience and consistence by putting the components in the wrong place. Many "home hobbyists" have no more problem than I do getting and keeping very tight reg, because the presses I make and sell have the same micro-tuning I invented for myself. UNLIKE other companies(who make presses that look like a UFO landed at your house)I have used the logic of 1.) very fine tunable and 2.)ON screen micro-tuning. There is NO other/better place(since that is where the image is)to get and keep registration. Look at the $40,000 and up auto screen print presses...they use a registration system that surrounds the screen. Manual rotary press companies never learned that lesson. Look at decal and poster etc printing...it depends on registration 'tabs' that surround the substrate(since the screen is stable already, unlike on a tee press). Yet it can be the most accurate printing method. It is TOTALLY counter-logical for companies to produce rotary screen printing presses in the way they have done so for over 35 years. They have made spinning from screen to screen primary over print quality/registration! Dumb. Unless you have a '97 Workhorse(huge and expensive)or an M&R Chameleon('huger' and more expensive!!)you are fighting to reach and keep registration, and wasting shirts and cleanup realignment time. I have seen it for too many years and on virtually 'every' rotary manual. I have sold so many of my presses due to being able to prove that...from my kithcen counter top. When so many 'pro-shops' could not. Those who do not believe it(and there have been plenty)have not seen it. Those who have seen it...DO say "wow!" Glad to know you have some SP savvy! I have actually removed most of my posts due to the slams from those who do not want top know/learn or accuse me of being a big headed spammer!? I have no need of being either. I learned everything I know from many years of hard work. I am HUMBLE(some have actually called me a "genius", 'tinabobina'! But I never said that till now because I AM humble...though YOU say I "suck" for my posts!?) and glad that I thought of the invention I did. I have been very happy to gain it's advantage and help many others out. I appreciate YOUR courtesy Garage Printer. Otherwise it was a waste of time to post here, it appears. Keep an eye on You Tube. I have made some little changes to my stuff. Since YT only allows 10 mins of vid I have to redo some vid(instead of post what I have on dvd)to work better with that time format. I print from my kitchen and make great money. MORE...I have FUN. I once printed out of a beroom using one screen and air dry flock adhesive. I was printing a photo(FA through a 240 mesh!!!it looked great though most would never attempt FA on high mesh) with some text(a political tee)...hanging them to dry as I went out on the street to sell them to others. I made about $400.00 profit in three days! I know what it is like to work every size and challenge. Nowadays...my car(right now, a kayak in construction)goes in my garage. Small and smarter was the best change I ever made to my SP doings. Best to ya' (: REPLY[flag][delete]

[garageprinter]

Let us know when you post it to youtube. We would love to be able to park a car in the garage again!

[_megankish__]

Hi! I'm so thankful that you've posted this tutorial! I did screenprinting in school and was considering purchasing a GOCCO for my wedding invites! However, I just couldn't bare spending $200 or more on a machine they don't even make anymore! Anywho, as it's been a while since I've done this, I have a couple of questions: 1. The emulsion, you let it dry for about a 1/2 hour. Then, once dry to touch, I can place my screen face-down (so that it's touching black fabric), place my transparency design on top of the screen (so that the text reads left to right, like normal), place glass on top. 2. So, when I set my screen and design in the sun, it dries the emulsion EVERYWHERE THE DESIGN IS NOT? Is that correct? 3. Then once the emulsion is hard, the area where my design is SHOULD WASH OFF... correct? Does the rest of the emulsion stay on the screen? I want to use this process for my wedding invites. My hope is to print them onto 100% recycled cardboard cd wallets. Not sure if I'll get them all done in one day sooooo, WILL THE SCREEN STAY AFTER SITTING IN THE SUN? Do i have to do anything to procure my screen to keep it "healthy" when I'm not using it? THANKS SO MUCH and your response will be greatly appreciated! x.o._x

[SpotMatrix]

Hint. To make sure you screen is good and exposed before printing but after cleaning, leave it in the sun for 5 minutes a side. You won't have issues with emulsion break down while printing.

[tracy_the_astonishing]

You have understood everything perfectly. The screen will last for years and years. You have to use a solvent if you want the exposed emulsion to come off. Just keep the screen clean. Don't let any ink stay on it after printing.

[revcdub]

Plastisol inks never dry, so you can put the screen away for years without cleaning it. Big time (and solvent) saver.

[SpotMatrix]

They don't fully dry but the do dry to a kind of lipstick dry. Not nice to clean from the screen. I wouldn't leave plastisol inks in the screen for more than a week. Tape is also an issue. the longer you leave tape on your screen, the harder it is to remove and will leave a glue residue.

[_megankish__]

Oh, an additional question: I'm reading that it's important to also have a bit of space between the screen and the surface you're printing on. I'm looking to print on Cardboard, do you have a recommended space? Is there something I could use? I hear screws in the four corners work well so you can adjust the height if needed. ANY SUGGESTIONS? THANKS!

[mtmob]

Off contact can be achieved by taping quarter to the bottom of the screens, its the perfect amount of off contact. Off-contact prevents the screen from stick to subject being printed. --James www.midwestscreenwear.com

[SpotMatrix]

The space is called "off-contact" and is required when printing on garments with plastisol ink due to the inks properties and peanut butter consistency. Printing on paper with waterbased inks.... I can't see any reason that it would be required but my experience is with fabrics.

[tracy_the_astonishing]

Screws sound perfect to me. The space is especially more important when printing on paper. With fabric it seems to matter less.

[genericpoptart]

First off, you are my personal hero for posting this. I'd have gone out and bought one of those $300 Yudu things if not for this instructable. I've seen on the Speedball instruction sheet and on some other instructables that you can use a 150W lightbulb or something to do the emulsion exposure indoors--what are your thoughts on that? (I've been stuck waiting for the weekends just to try and get good sun for the exposures, and I'm getting impatient to make more designs!) "slimguy379" says he uses that on his DIY for like 15-20 minutes, but then again, he also makes his own emulsion so it might not work the same as the Speedball stuff.

[smallpurplefrog]

hey, i've gotten really nice results with a projector (you know the old boxy kind from school). i don't know if a plain old light bulb would work... maybe! let us know!

[sarahmharder]

i have a 150w bulb and a 10.5" reflector pan, and exposed the screens according to the directions on the speedball kit, and after an hour and a half, i noticed some smoke coming off the screen...it burned a hole right through the material ( i was using curtain fabric). you could try to play wit the distance of the bulb from the screen, but it will likely take a lot longer to expose the whole thing.

[sparkly_vagabond]

Ok I have just started looking into this and wonder if the process where you trace your design onto the screen and then paint with modge podge (excluding the areas where your design will be) will actually work. I do not have sunlight much at all here (Alaska Bush) and even if we did the screen would freeze within seconds. Is there another way to burn the design into it and another way to wash this off? I don't think using a hose outside would be wise for me. Any advice would be helpful.

[tracy_the_astonishing]

I'm not experienced at burning a screen without sunlight, but a UV lamp ought to also work if you have one. There are some comments about burning the screen with artificial light. I was trying to do it with a halogen at one point, but that's not UV and I thought it was working because the sunlight coming in through the windows of my apartment was exposing the emulsion. I've done this process indoors in the winter in Boston. I burned the screen with sunlight coming in through the windows, and then I washed the screen in the bathtub with the shower head.

[labo]

how many sensitizers mix with emulsion?

[beeyalen]

i have emulsion that was sensitized a couple of weeks ago, and it worked fine. the other day i tried to use it, none of the emulsion washed out after being exposed. i'm thinking it might be one of the following: 1. I opened the bottle of emulsion in the light (only for a few seconds though) 2. I exposed my screen for too long 3. the emulsion is too old I'm thinking its #3. It was originally green, but has now turned blue, the same color as the part of my first screen that didn't wash off, and the same color I believe it was before I poured the sensitizer in. Could the emulsion be re-sensitized?