Resinotype

I opened this new thread following the one on graphite ( (there was a url link here which no longer exists) ).
I started experimenting with resinotype, following Alberto Novo's instructions ( http://www.alternativephotography.com/process_resinotype.html ) and some advice from Loris. By the way, melting the colophony in alcohol is a great solution for heat sensitive pigments, but for more stable ones heating the resin is much faster (also you don't have to worry about grinding the colophony in advance).
Alberto, though, is not very clear whether the gelatin should be hardened (i.e. Glyoxal or formaldehyde), and if yes, at which point.

Bye
gm

I found this article online from an Italian magazine, which explains the gelain sizing for oilprint (which has the same basis). The gelatin layer should be thick and dense.

- Soak 6g of gelatin in cold water. Let swell for about 20 minutes until it is soft.
- Heat 100ml of water at ~60°C and pour the [I suppose, drained] gelatin a little at a time, stirring with a spoon.
- Soak the paper in hot water for a few minutes, then lay it on a flat, levelled surface (like a glass plate), after having removed the excess water.
- Pour the hot gelatin on the sheet with a spoon, spreading it with the bottom of the spoon. Avoid spilling outside the sheet borders.
- Remove any air bubbles by poking them with a pin and leave the sheet flat until the gelatin hardens. This may be several hours.
- test the surface on a corner of the sheet, touching it. The gelatin should be soft but firm. Hang the sheet to dry, for up to 24 hrs. if needed.

I have a doubt: does the paper need to be acidified?