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Showing posts from 2015

Cyanotypes. It's always something.

A photo posted by curtis corlew (@cccorlew) on Dec 11, 2015 at 3:04pm PST

We finally have our cyanotype coating figured out. We use a sponge brush, coat once lightly, let it dry a while, then coat again. It uses more chemistry but makes for darker blues and a smoother less dotted surface.

We have paper that seems to work. The Strathmore Mixed Media Paper has a nice weight and isn't breaking the bank.

We figured out the adjustment curves in Photoshop and printing digital negatives. If we aren't spot on, we are pretty close.

We've figured out that the time of day as well as the season change the amount of UV light to the degree we need to do a new exposure test every time we print if the time of day or date change much.

So what's wrong? We've been using an Epson 1270 to make our negatives. My new MacBook running El Capitan is incompatible with Epson 1270 printer drivers and won't work at all, so we need to get a new printer and start the calibration process all …

Yellow stain on cyanotypes. Problem solved!

At last, a problem with a solution. When we first started coating paper with our own cyanotype chemistry we were getting bad yellow stains. It turns out there are two ways to combat the ugly yellow. One is to add citric acid to to the first water bath when developing the print. The easier way is to add a bit to the sensitizer chemistry itself. We'd done that, but it turned out we hadn't been adding enough. So now, the yellow you see in the above print is a thing of the past. One problem solved, eight zillion to go.

Cyanotype success, or a step in that direction

We are getting closer. Of course, if the clouds would be consistently gone and the UV radiation consistent life would be easier.

But it does seem that really coating the paper heavily with a sponge brush works better than using a glass rod. More seems better. We've been guessing at the curve we need to make the neg work, and we seem to have one for this photo. Whether it works for all or most photos has yet to be seen.


This curve opens up the shadows just a little makes the highlights not as bright. It and isn't nearly as flat as the ones we've seen offered as "standard" cyanotype curves.

Of course, it get's an invert adjustment layer on top so it will be a negative.

We'll adjust as we learn more. But as they say in Westeros, "Winter is coming." which means less UV and more clouds.

Ultra Violet and the lack there of

Pre-history

In the beginning there was sun print paper and laser print transparency negatives. And it worked. Well, it kind of worked. It was a miracle.  But of course it wasn't enough. It was just a taste of the possible. A sly inducement to to try mixing chemistry and coating paper.

Buying the New Cyanotype Kit and mixing the chemicals was a challenge, and the results were less successful. After near endless failures it seems that perhaps the paper, an expensive etching paper, was to blame. 
In 2015 we started over. After more failure we realized that we needed to print our negatives in color ink on the aging Epson 1270 we're using, and not only black ink. Apparently using color blocks UV better.  We also discovered using any old transparency material didn't work. We switched to  Pictorico TPU100 Premium OHP Transparency Film, which costs almost $1.00 a sheet.

The book "Easy Digital negatives" proved to not be as easy to implement as the title implied. but it helped. We ha…