Carbon Printing Continuous Tone Highlights

[sanking]

So in practice, one can find the threshold at which "paper white" begins base on a particular tissue, sensitzer dilution, etc. Perhaps having a black bordered mat board can provide the illusion of whiter densities on an image.

Thank you Sandy for the clarification.

Correct, the highest highlight that can be printed, without mechanical break-off, depends on a number of factors related to process control, including tissue, method and type of sensitizer and dilution, type of negative, etc. It really is not necessary to leave a black border to give an illusion of white since with reasonable process control one can control highlight density to 1/2% - 1%, and the difference between 1/2% - 1% and 0% can only be seen when the two are directly compared.

I am attaching a scan I just made of a recent step wedge print, including a 21 step wedge where each step is different from the next by 5%, and a 50 step wedge, where each step is different from the next by 2%. As you can see, in each each case the step that corresponds to 0% (and paper white) is actually about 1%. I could adjust this down to about 1/2%, with a slightly greater risk of the mechanical bond breaking somewhere between 1/2% and 1%. However, in fact it is fairly rare that an image would need to show highlight even down to 1%. The carbon step wedge print were exposed with a digital negative made with an Epson printer using a custom QTR profile.

The concern about printing highlights down to 0% is an issue for color work, but in my opinion not with monochrome carbon, unless for some reason one just must print down to absolute paper white of 0%.

Sandy

[ghostcount]

Thank you Sandy for the in depth explanation.

[Andrew O'Neill]

It's very challenging, but not impossible... personally, I've found it way more challenging with inkjet negatives than film negatives...