One of the most asked questions we get in our office is about eps files.
Encapsulated PostScript, or EPS, is a PostScript document with additional restrictions intended to make EPS files usable as a graphics file format.. Now, just because you have an eps file doesn’t really mean that it is ready for printing. You can have the worst looking artwork and save it as an eps and that doesn’t make it usable.

The best way to do a graphic art is by doing it as VECTOR ART. Vector graphics are files that you can size up as many times as you want without losing its quality. The main programs in which to create vector files are Illustrator, Corel Draw and Freehand. In a perfect world all your customers will send you their logos as a vector file with the fonts converted to curves. But of course, we don’t live in a perfect world so most customers won’t even know what a vector file is. Most of the time they give you jpegs, bitmaps, Microsoft word, publisher and the occasional, rough scans drawn by monkeys (believe me we’ve seen it all). In this case, what we do as graphic artist is to convert those files into graphic or vector files. Like you used to do when you were a little kid, you take whatever file they give you and lock it in the program that you are using, and then using the different tools you try to re-create as close as possible to the original. However there are some downsides from using vector art, for example, you cannot really do stunning effects without going into Photoshop. Once you export a file into Photoshop you can kiss that vector art goodbye. So I always recommend to export it as a good resolution (at least 300 dpi) and at the actual size of what the final product is going to be.
Below you can see the difference between a vector art and a raster image (which include Photoshop, bitmaps, and jpegs)


Tips:

I think screen printing is sometimes treated as the rebel adolescent child of the industry, I mean think about it when the ad agencies do posters and ad campaigns they put all their effort into doing the best looking artwork and everything is taken into consideration. When they do art for shirts, they usually send you the lowest quality looking art they can find. It’s like they think we are some sweaty, smelly, bearded fat guy with a beer in one hand working in some dump looking underground warehouse (wait, I think I just described my best customer Willy, sorry Willy it’s nothing personal, although you could use a shower once in a while) .

When we went to Art School, there was no class called “t-shirt graphics” or “how to prepare files for silk screening 101” . The main thing they used to teach us was to create art for offset printing. So we had to figure out how to use the knowledge and then translate it into the dark side (the screen printing business). It took several ruined arts, and many disappointed customers until we could really do graphics for T-shirts. We think there are just way too few places where people can go and get knowledge of screen printing. It really is an art and I really admire those who work countless hours in front of a screen, and get all dirty and then sometimes get little or no credit for their work.
The main thing to remember when you are preparing graphics for separations is to convert your colors to SPOT COLORS. When making a multi-color print with a spot color process, every spot color needs its own lithographic film. All the areas of the same spot color are printed using the same film. The dot gain, hence the screen angle and line frequency, of a spot color vary according to its intended purpose.

HOW TO CHANGE FROM CMYK COLORS TO SPOT COLORS

The preset colors you see on the swatches when you open illustrator are CMYK or RGB colors, to convert them to spot color simply double click on the color and the swatch options window appear and where it says “color type” change to “spot color” and click ok. You will notice a little dot appear right on the swatch, that means it is a spot color and it is ready to be separated as such



Just remember that even if you have all the colors converted into spot and you want to separate from your printer, you still need a postscript printer. We have always used Hp 5000 series. They are great because they are able to print a little bigger that tabloid size and they are very fast and they can last a long time.

What is PostScript?

Simply put, PostScript is a programming or page description language. It is a way of describing what a page should look like. Another such page description language is PCL (printer control language).

Printers print dots. How these dots (raster images) are arranged on the page determines what you see, how the page looks. A printer uses an interpreter (printer driver) to translate digital documents created by your software into a raster image that the printer can print.

You would need a postscript printer to print halftones. These are usually laser printers. You can “fool” an inkjet printer to print halftones with a third party program like “Fast Rip”. That is the program that we use with our epson 3000 inkjet printer. The downside of these printer is that the film is not water proof and it usually takes a long time to print compared to the laser printers. So I recommend that if most of your stuff is under 11 x 17, just go for the laser printer.

In order to print the separations and be able to burn screens from them, you would need to use a translucent paper called vellum. It comes in different sizes or you can just cut them yourself. The vellum that we use is very good at holding registration. We’ve had artwork that is about 2 years old and people come back to us because they need a white flash, and guess what, after 2 years it still registers with the original. If you need to find out our supplier, just check in our resources page for more information.