Quote Originally Posted by banana_legs View Post
Hi,

I have had the same problem of loss of highlights and it can occur if the sizing on the paper is not hardened quite enough; I think of the problem as a 'micro frilling' issue where the very thin highlight gelatine does not quite stick well enough to the support. The sizing is hard enough to stop much of the frilling issues, but not quite strong enough to hold onto the highlights. Try painting on a 5% solution of formalin onto a sheet to harden it some more and see if the highlights change.

I also have had the problem when the mating bath was too alkaline and the gelatine sizing on the paper gets a slightly 'slippy' feeling in the mating bath. A dash of citric acid solution (e.g. stop bath) can help in this case and I now slightly acidify the mating water routinely now as it always seems to have a positive benefit with image adhesion.

Best regards,

Evan
I have tried with acidifying the mating bath, but the problem still persists.
As for the substrate hardness, that's interesting - I just gave my paper a further formaldehyde coating. In this case, is it advisable to rinse the paper after it has hardened, so the formaldehyde doesn't seep into the carbon tissue during mating and harden it?

Attached is a detail of a print where the highlights appear as a white pool - yes, the negative is very grainy, but I would still expect a smoother gradation from light grey to paper white.

Thanks
gm