Screen Printing?

[Jacob Kobryn]

Hi,

Can anyone please give me links to posts or tutorials about screen printing? I have done some simple screen printing in class but I'd like to learn much more about it. This will be mostly for posters but also the occasional t-shirt.

Specifically, how does one screen print a multi-level image such as Stephen Kasner did here?

http://www.stephenkasner.com/images/khlyst-i.jpg

I'd like to learn how to screen print but I dislike the graphic nature of most of the images. I personally like to create images with many values and I'd like my screen prints to be no different.

Thank you,
Jake

[Aphotic Phoenix]

Possibly done with photo-sensitive emulsion, and multiple screens. I used to know how to do emulsion screen prints, but it's been so long I've forgotten.

Here is a .pdf that shows a lot of different serigraphy techniques: http://www.scottkolbo.com/printmaking/Printmaking%20pdfs/2X4%20book.serigraphy.pdf

*edit* I should point out that printing on t-shirts is FAR more difficult than printing on paper, and has different requirements due to the differences in "ink". From what I remember, even advanced printmaking students were discouraged from attempting multi-screen t-shirt designs because it's difficult to register them properly without the right equipment.

[DigitalShade]

The method used depends on the color shirt and the end result desired.

There are special printers that will print directly on the garment. They have good gradation but the vibrancy of the color is not as good and doesn't last as long.

Then there is the photo sensitive method. It involves knowing how to color separate an image and adding registration marks or using software that does the separations for you (which I wouldn't recommend, bad quality). You'll need to break down the colors into channels, subtract out overlaps of color that are not wanted, and print them out in half tones on vellum. Then apply them to the screens by the photo sensitive process. That pdf you posted shows a rough way of doing it. The place I worked at we had a machine that created a vacuum that held the vellum flat against the screen while the light changed the emulsion. Pressure wash out emulsion, let dry, then use for printing. Each color is applied one screen at a time.

If it's a white or light shirt you can break the image down into a cmyk image and use process inks that are transparent. This way you get a lot of colors with fewer screens. CMYK would be 4 screens and you would add additional screens for specific colors that you cant mix via the cmyk inks.

Black or dark colored shirts are different you have to lay a white base ink down on the shirt then add your colors above it. The more colors the more expense and time involved. The max amount of colors would depend on the machine you are using for screen printing. For example the machine we used had a max of 7 colors that could be used.

A vast majority of work is done in vector programs like Illustrator or Freehand. Colors are set up as spot colors, it makes it easier to change colors latter if needed and art can be scaled easily without a loss of detail (pixelated). This is why a lot of screen printing has that graphic look.

Separations for photographic images are done typically in a program like Photoshop. Use an appropriate resolution and size for printing to achieve good prints. You will usually have to tweak some screens after a test print. They don't always come out how they look in the computer. Color separations are a bit of an art of their own.

[Viridis]

The reason that screen printed images are so often graphic is that it's a pain in the ass to make the screens necessary to do very subtle gradations. The only real way to do subtle gradations like that is to use a photo emulsion on your screen and do photo transfers... which is not something that's easily doable at home because it requires UV lamps and a darkroom.

Honestly if you want to do printing and like more subtle, shaded designs I'd recommend Lithography on paper prints rather than screen printing. Or possibly etching. Of course, either of those two methods tends to be more toxic/involved than screen printing, and not something you can do at home.

[Ilaekae]

The best way to learn screen printing is from one of the books readily available on the market. You have to constantly refer back to it, especially if you're doing photo-emulsion work. Most aren't that expensive, and I'll check through my crap to see if i can find some to recommend.

Registration is done with little pieces of tag stock or thin brass that are taped to the board to catch and guide the paper for each color pass. I can make you a quick sketch to show you what it looks like if you need it.

BIIG suggestion...You can work with extenders (transparent "color thinners") that allow you to get all kinds of interesting "water-colory" effects but it's difficult to repeat the process, so everything becomes one-of-a-kind. You simply toss the ink on the screen in appropriate places and use the squeegee less as a flat scraper and more of a "wiggle it up and down/stop/lift/go back/turn sideways" kind of tool.

[Erika111]

Hello,

I would recommend considering screenprintedtshirtdesigns.com, you will get more ideas for more shirts graphics.Screenprintedtshirtdesigns.com is t-shirt printing, silk screen t shirt printing and custom printed t-shirt company. They specialize in screen printing, embroidery and similar services. They offer incredible pricing, free shipping and lot more.

[kab]

Printing an image such as that one would require a good photosensitive emulsion and a fine mesh screen (I'd guess atleast a 230 screen, that's 230 threads per inch) per color. Also, an exposure-rig with a vacuum would help to ensure proper contact when exposing film (this is very important when you're working with halftones). Then you'd need to do separations of each color in the image as a halftone image, or do a cmyk (but that won't give you the same vibrancy of color, since process inks are transparent), there are programs to do this reasonably well, some are free. I recommend you use solvent-based inks, as they don't curve your paper, which is obviously a bad thing when you want tight registration, having to press your sheets between colors messes up your reg-marks.

Then you print your seps, all black, onto a clear substrate, preferably using a high-quality ink-jet printer. Then you burn your screen and wash it out, being very, very careful to not mess up your halftone, they wash away easily if you have mis-timed your exposure, then just tape it up and get printing. To do multicolor prints, you need good registration, there are home-brew ways that do the job, but if you do many screens (I'd say more than three or four) I'd try to use a printing table with a vacuum and micro-registration, or you'll always be off unless you really know what you're doing.

Also, for halftone work, a coated paper-stock would be the safest choice. If you use a uncoated, coarse paper you might need to do some trials to figure out your printing pressure or maybe even use a softer squeegee to get a good result.

Printing shirts is a whole other beast, requiring special inks that in most cases need to be cured using heat (i.e. expensive conveyor dryer being your only choice) and flashdrying of ink-layers between colors. You need a carousel press (several platens, rotating screens or platens) to achieve any form of registration, it's basically a bitch, and printing CMYK on shirts is better left to the real pros, I've done some graphic shirt printing using air-dry inks, but they are solvent based and will melt your brain, fast.

Any printing with half-tones, textile or paper, is a high-precision job, requires good equipment, trial, error and is not for the faint of heart. You will make mistakes, and you will need at least a six-pack of decent beer to get through it. :)

Feel free to shoot me a PM if you still want to try and have any questions, I have a bit of experience and I'd love to help you out. Also, the guys over at http://www.gigposters.com are extremely knowledgable and are willing to help, but I suggest you read a good deal on those forums before you post, as they are professionals who take their craft very seriously (thsi goes for most screen printers I've met actually) and love tearing newbies apart, trust me, I know. =p