Sunday, September 23, 2007

Problem Solved?

Well, it’s been a frustrating and very stressful week, but I think I have my printing and calibration problems nearly solved.
If you read my last post, you’ll know that I’ve been working on printing digital negatives on transparency film. After several false starts and other problems, I got the transfer curves right, but was getting banding in the 13 X 19 transparencies made with my printer.
Here’s how the banding shows up in a cyanotype print. This should be a continuous tone area, the stripes you see are the result of banding in the transparency.

The banding in the transparencies looked like it was occurring with the color inks (not the blacks), so I switched to true grayscale for printing (no color inks). This meant that I had to do the transfer curve calibrations over again, which meant three more versions of the test negative and print you saw in the last post.
I got a good looking sample print, but the 13 X 19 negative I made still showed banding.

So, I tried aligning the print heads, first automatically, then manually. I cleaned the print heads several times, changed several ink tanks ( I used several tanks of ink while figuring this all out), and still, banding in the transparency prints. At this point, I started getting really stressed out. I was running through lots of expensive materials, and kept ending up at the same spot. I was also stuck, and could not progress in my work, for what was going on three weeks. I called Epson tech support, but that was a waste of time. They told me that maybe my blank transparencies were dusty, and other useless suggestions that indicated they had no idea what the problem might be.

All this time, 8 1/2 X 11 transparencies were coming out mostly ok. It was the 13 X 19 ones that were banding. That suggested to me that the problem might be the way the large transparency sheets were feeding through the printer.

The Epson printer driver has no setting for transparencies. You have to guess what to set the driver at when printing them. The Epson tech support guy told me that Epson does not support any media that's not made by them. They don’t manufacture 13 X 19 transparency, could not recommend another brand, and had no advice on how to set the print driver. Figuring I had to try something, I decided I had to make test prints using every paper setting available.

I didn’t want to blow through another ten or more sheets of 13 X 19 transparency, so I selected several 2 X 13 swatches of an image and printed them on the same sheet of transparency film while varying paper settings in the print driver. For each new setting, I ran the same piece of transparency through the printer. It only took a few tries before I found a setting that resulted in minimal banding. There’s still a tiny bit of banding, but not enough to show up too much in a cyanotype print, as you can see here.

Because this is a different paper setting than I used before, I have to go through the transfer curve calibration a third time. I’m getting to be an old hand at it now, so it shouldn’t take too long. Once I get the correct curve, I’ll try printing a 13 X 19 negative. I’m optimistic that this will work, but I’m also not getting my hopes up, just in case.

I tried not to let the talk get too technical here. If anyone is trying something similar, I’m happy to offer more detailed advice. Send me an e-mail or leave a comment, and I'll help if I can.

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