Chrome alum sizing, was Re: sizing with glyoxal

Chris,

Actually I size my papers with chrome alum by brush coating, not with
tray soaking.

Never had any problem with residual blue color, or with streaking
doing this. I use about a 3-5% gelatin solution and about 2g of
chrome alum per 1000ml of solution. But I don't add the chrome alum
directly to gelatin solution. Rather, I first mix it with about 150ml
of warm water and dissolve it completely. Then I add the chrome alum
solution, very slowly and with constant stirring, to the gelatin
solution.

Sandy

>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 09:44:47 2004