My understanding is that you don't want to penetrate the paper as the image will either be unsharp/fuzzy, or if it penetrates too far the image will print straight through the paper and will look funny.. I don't like sizing, I try to find papers that don't require it. I have stored sized papers for about a week or so (gelatine and arrowroot) with no major problems.

If you want a deeper/richer look coat it's usually best to coat twice.
I've stored presensitized paper (VDB and cyanotype) for an afternoon. By the end of the day it was just about unusable. I like to keep it wrapped up in aluminum foil. It does seem to keep better wrapped in foil then placed in a ziplock bag.

VDB is pretty easy but it's 'hard'.. I don't know, my problems come up as soon as I fix the image. I always used the fix straight.. I was never sure if I had to dilute this to working strength.

Occasionally i'd get bits of metal, etc. on my prints. banding, splotching.
The next print (processed the same way) would be perfect.
Some would be warm light brown/orange, others would be the warm dark chocolately brown that you'd kill for in a RC or FB paper + toning (even when coated and processed the same way!)

I'm not sure but I think humidity plays a key..
It's as easy or difficult as you make it.

Quote Originally Posted by Eston3 View Post
Before I make that mistake, why is "sizing" so important? I would have thought that you would want the emulsion solution to penetrate the paper, mabe achieve a deeper richer saturation/color from actually being imbedded in the paper. And while we're on the subject, can you pre-size the paper and store it for coating with the emulsion at a later date?