sizing with glyoxal

Good morning all!

I sized a bunch of paper with gelatin/glyoxal. I don't have formaldehyde
and have been scared off of it by comments on the list. I will say, tho,
that the paper that I had that was sized that way was wonderful, and it just
ran out.

I have sized with chrome alum and was not thrilled with it much. It left a
pale blue color and streaked, plus it held in the dichromate stain. This was
with brush coating, and I know Sandy King does wonders with chrome alum and
tray soaking so I shouldn't diss it until trying it this way. There was
one author back in the day who said a chrome alum *clearing bath* increased
the grain in a gum print (as opposed to using pot metabi, sod sulfite, etc).
Who knows if this is myth or not? Most people nowadays don't use chrome
alum for clearing anyway, if they even clear (I don't anymore).

I went back to glyoxal. I used Livick's thermos method: 30g of gelatin and
1000 ml of water brought to 140 degrees, and then 25 ml glyoxal added.
Poured into the thermos, it is still 120 degrees 15 hr later, so it is a
good way to size in bits and pieces (between movies and layers and not
having enough room to size 36 11x14's at once).

I brush it on, no streaks. Two coats. Also, no curling of paper because of
one side only being coated.

However, one observation I'll have to corroborate the next time I size: the
glyoxal gelatin solution seemed yellower today than last night. Whether
this leads to any explanation of the yellowing controversy we have discussed
here, who knows. It was kept at 140-120 degrees for 15 hrs and is yellower.
Any suggestions, chemists and gum printers? When brushed on the paper, the
yellowing in a thin coat of size is not apparent so no biggie. Plus I'll be
using it right away so it won't sit in a drawer to get yellower...
Chris
Received on Sun Feb 15 09:14:00 2004