Shuttle, Ware Cyanotype © 2012 18pct
This is just a test print from re-calibrating my QTR profile for Cyanotype using Chartthrob.
Chartthrob produces a curve that’s meant to be applied to a positive image in photoshop, however QTR requires the raw curve for the end product (i.e. negative) to control the ink. This means you have to find a way to invert the curve in order to use it in a QTR workflow. You can either do this by hand, or use a relatively obscure trick with photoshop to do the inversion for you. The same technique can be used to merge two curves — such as when you would want to apply a second-pass of chartthrob to your original curve. I’ll put together a quick tutorial in a future post.