Hello everyone, I would like to know how can i cover Guar gum on the surface of my normal printable paper Is there any simple method to do that ? ( I don't have sophisiticated tools with me :S but i ask this because i heard that gum protects the paper ) Thank you guys !
Use gelatin (Knox's or photo grade, 200 -250 bloom). Put 30 grams in 500 ml distilled water. Allow to swell for 20 minutes. Heat over a double boiler until gelatin has melted. Apply by foam brush, coating blade, or immersion. hang to dry. If double coating, you must harden the intiial coating with formalin or gyloxol. NWG
Hemphrey, your choice of sizing material intrigues me. Why are you thinking of guar gum? I've never heard of anyone using it for a size, but that doesn't mean I don't think it would work, it just means you may need to do the legwork yourself as far as experimenting with it. And what process do you want to print on the sized paper? For gum printing, gum arabic can work as a size if it's crosslinked so so as not to be soluble in water. Some people mix it with dichromate and expose it to light to crosslink it; that's more trouble than I want to go to and I crosslink it by mixing it with glyoxal when I've used gum arabic as a size. Not being familiar with guar gum I have no idea how similar it is to gum arabic in structure, solubility, or how well it crosslinks as a dichromated colloid or with a crosslinking agent like glyoxal, so it's impossible to tell you how to use it as a size, sorry. Katharine
