Gum, sizing, formalin crosslinking time?

[Loris Medici <mail@loris.medici.name>]

I finally managed to get good results with sized paper.

Before, I was sizing with 3% gelatin (>= 200 bloom, formalin added to hot
solution) and no matter how thick / thin I coat and/or how much I expose,
I was getting flaking, layers that won't stay on paper and poor tonality
with sized paper. Therefore, I was using unsized paper (Fabriano
Artistico) despite the staining problem. (Unbearable especially after 3rd
printing...)

Now, I size with only 1% gelatin and the results are super! No staining,
robust layers and good tonality. (Thanks for the suggestion Christina!)

I'm out of sized paper and will size a new batch of paper. Question is:
how long should I wait for the gelatin layer to stabilize/fully crosslink?
Can I use the paper as soon as it is completely dry or should I wait more?
(Remember, I use formalin in hot solution as hardener.) The paper I got
good results was sized months ago, and almost all my previous attempt were
made with paper that was sized the day before printing... So, now I'm not
sure if also aging has some effect on my success.

What do you think, what is your procedure? (Especially for those who
harden using formalin.)

Thanks in advance,
Loris.

P.S. Results with unwaxed plain paper negatives are good -> but midtones
and highlights are too grainy/harsh (due to paper structure), I can't be
pleased with the results for monochrome work. Will try tricolor and see if
that's OK (I hope color + using 3 or 4 different negatives will mask /
lessen the unwanted grainy effect.