2010.03.29

Inked all over

23.27.32 - Mark

Last week I posted Inking, part of it my history with screen printing shirts, part as attempting a short timelapse video of preparing the negatives for a few screens on some vellum paper. Aside from my own screw ups, the the DIY Screen Printing Instructable was a good resource I used though the entire project. However if it's your first attempt, don't start with your favorite project.

The first of the four screens I did ended up with a lot of pinholes in the screen's mask after washing it up after exposure. I was also stupid enough to ignore the pinholes and do a test print.

Pinholes in Screen Print MaskTest print with pinholes in screen print mask

A small art-style paint brush and more of the photo emulsion goo I was more or less able to remove the pinholes with a couple passes. Once it was done I started preparing the other three screens. However these I either spread on the wrong amount of goo and fell though, or the goo had been partially processed with light and didn't expose. In either case I only noticed it after I checked the dried screens, and the holes were too great to bother repairing, so they all got a heavy bleach water wash and a fresh round of photo sensitive emulsion (this sort of screw up and I was extremely pleased with using the homemade mix of Potassium Dichromate and Elmer's Glue instead of buying commercial products.)

The second batch worked and I applied the art, then set off to printing, and learned another lesson (or three).

First don't print them by yourself. In the past, I didn't print more than one or two on my own. I either paid for a company to do the prints or worked with a friend to make the prints. In this case I did 36 prints (9 of each screen), and it would have gone a lot faster if I had an extra set of hands to handle either the fabric or manage the screen and ink.

The other lessons would be a good workplace with good tools. Since I didn't have a table that could be used, and raining like crazy outside, I made the prints on the floor. Works well enough for small runs, but as many prints as I did it wasn't comfortable. Same sort of goes with tools. While the kit I had / made was fine, I needed the ink to dry before I could stack it. Without suitable shelves the "solution" I should have worked on setting up a drying rack or a heat treating system. C'est la vie.

Despite all these problems and lessons, and a couple mistakes on the flags I was printing, all 36 are good enough to use, since the friend who asked me to do all this work was half expecting to loose 5 or 6.
Most of the 36 prints made in this project

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2010.03.18

Inking

20.34.11 - Mark

A few years ago, one of my brothers bought a screen printing kit, the two of us figured out how to print some t-shirts, and planned on doing more with screen printing. Didn't quite happen. The parts have been reused to projects, but screen printing fell off to the side. The cloth prints since then were either one-off with freezer paper stencils and spray paint (similar to this project), experiments for other techniques, to simply being large enough that a professional lab felt more practical than an attempt at DIY printing on a short time table. However, about two weeks ago a friend asked me about printing some flags.

He'd used professional printers before, but the low number and small size meant it would have been pretty pricy, and while at first I figured stencils and spray paint would work (and it would) the numbers are enough that DIY screen printing would be easier. So I started working on the kit.

Unfortunately parts of it didn't age well. The screen, ink, and tools are in good enough shape, although quite probably not enough, and the photo sensitive emulsion chemicals were either missing, or used. I was also missing the manual. I know, oft ignored, but if you're playing with chemicals its wise to do your research. In this case I turned to Instructables, and landed on the true DIYers screen printing project. While it isn't the most precise article, it's a great guideline, both for people doing it themselves and those who want to save money.

So while I was waiting for the Potassium Dichromate / Elmer's glue photo emulsion to dry onto the screen, I started working on the art. In the past I'd dig up a piece of transparency sheet and use that for the mask, but finding any, and not liking the price I deiced to try vellum paper (in large part due to the DIY screen printer instructable). Which gets me to this video.

Since I'm working off a vector art piece, I wanted to print it on to the vellum. However my printers don't run on cheap ink, so I only printed out the outline, and would fill it in by hand. Right before I started filling it in I pulled out my old point and shoot and set it up for time-lapse.

Nice short and simple video, in many ways very similar to the Pennies video I. [wow, over 4 years ago!] The slight difference is I had the camera set on time lapse, in one shot a minute factory issued mode, so this ends up being choppier than I'd prefer. I'm not sure if I want to blame my lack of (good) camcorder, better knowledge of the CHDK hack for my point and shoots, or the extended lack of a intervalometer controller for my DSLR (be it commercial product, graphing calculator, arduino based project, or a crude but simple 555 electronic circuit)

In any case

Inking (4.4MB 320 x 240 H.264 Quicktime)

Creative Commons LicenseThis work is licensed under a Creative Commons Attribution-Noncommercial 3.0 License.

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