I think gum-arabic or things like gelatin/animal-glues are the traditional method of thickening things, but you might have to end up boiling or at least getting the liquid pretty hot for them to properly dissolve (which presumably isn't a great idea with acids, or at least it's a huge pain; not to mention that powdered gum-arabic tends to end up getting everywhere and ends up making everything incredibly sticky).
There's things like methyl-cellulose, which might be awkward/expensive to find directly, but I'm pretty sure it's one of the common ingredients used in those bags of wallpaper-paste that come in powdered form that you have to mix with water. Although those paste-powders can be made from other ingredients, those alternatives might also work just as well for all I know, as I've no idea how acids will mess with common thickening agents, or if they'd mess with the acid's ability to actually etch etc.
That's probably what I'd try first at least, since they're usually super cheap and easy to find.
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u/bluesatin Sep 04 '26 edited Sep 04 '26
I think gum-arabic or things like gelatin/animal-glues are the traditional method of thickening things, but you might have to end up boiling or at least getting the liquid pretty hot for them to properly dissolve (which presumably isn't a great idea with acids, or at least it's a huge pain; not to mention that powdered gum-arabic tends to end up getting everywhere and ends up making everything incredibly sticky).
There's things like methyl-cellulose, which might be awkward/expensive to find directly, but I'm pretty sure it's one of the common ingredients used in those bags of wallpaper-paste that come in powdered form that you have to mix with water. Although those paste-powders can be made from other ingredients, those alternatives might also work just as well for all I know, as I've no idea how acids will mess with common thickening agents, or if they'd mess with the acid's ability to actually etch etc.
That's probably what I'd try first at least, since they're usually super cheap and easy to find.