Just for the records; the "overhardening" which I refer to is the phenomenon Colin thinks he is stricken by. (Where presumably more hardener than the ideal will make the sizing soften and cause more swelling...)

OTOH, it's interesting that glyoxal is able to harden gum but formalin isn't. I seems like formalin works with proteins only whereas glyoxal works both with proteins and polysaccharides!??? Anyway...


Quote Originally Posted by Katharine Thayer View Post
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I have seen overhardening of a colloid with a hardener, once, but that was when I was experimenting with using glyoxal to harden gum for a painting application, and tried several different strengths. The gum with too much glyoxal became very hard and crystalline on the surface when it dried, almost in texture as if it were coated with sugar or something. Again, not sure how relevant that is to the question here, just an observation...