DAS – Koraks tinkers

A ‘contrast ceiling’ of DAS carbon with continuous tone negatives

Previously, I have written about my attempts to make DAS carbon work well for continuous-tone negatives. The main challenge is highlight rendition, with flaking problems destroying delicate highlights. After testing many factors, I think the only conclusion left is that there is a limit to what DAS can do. Moreover, this limit is different (and more, well, limiting) than with dichromate carbon transfer.

Aching, flaking – A persistent problem with carbon DAS highlights

The problem that just won’t go away: disappearing highlights on DAS carbon prints. Twice so far I’ve declared this problem solved on my blog, only to have to revoke my ‘eureka’ shortly afterwards. Over the past few weeks, I’ve been systematically testing the process to find a cure. So far, to very little avail, I’m afraid. But perhaps that this writeup will (1) help me re-think the problem and (2) it’ll give some hints to anyone else struggling with DAS carbon problems by listing factors that can/should be evaluated.

Puzzling paper problem – A carbon transfer print surface anomaly

There has been this tiny problem bugging me for a couple of months. It popped up when I moved to DAS sensitized tissue for my carbon transfer prints. Some sort of micro-scale unevenness in tone. It reminded me a little bit of some form of reticulation – but not quite. But I think I’ve cracked this nut now, and it’s actually much more obvious and benign than I had imagined it to be.

Kind of blue – A test with UV LEDs for DAS carbon transfer

So the 400nm LEDs I had been using since October or so worked really nice for dichromate carbon transfer, but I ran into trouble with DAS carbon with them. Some further testing with my bank of trusted Philips BL tubes and a little theoretical exercise suggested that at least some 365nm exposure is needed to get DAS carbon to harden reliably especially in the highlights. So I’ve been testing a bit with 365nm LED options – two in particular that seemed attractive. This is a small report on these tests.

DAS right! – Solving the teething problems of DAS carbon transfer

Previously I wrote about trouble I was running into with DAS-incorporated carbon tissue. I just couldn’t get those tissues to transfer properly. Well, looks like I figured out why. In the process, I received some useful advice to boot, and perhaps there are some myths being established as well. Are you starting out with DAS and running into issues? Maybe some of the info in this blog can be of help.