Cover of a Knox booklet from 1914, and my one of my favorite pages from within.  It seems a very arbitrary thing to Inflammammal that gelatin companies consistently produced the most attractive advertising among grocery categories.  Such a humble thing, gelatin, and such a wealth of purty pictures.

Davis brand gelatin was an early competitor of Knox and Jell-O.  Here's the so-so cover of a 1918 recipe booklet followed by a nice illustration from inside, which I find very nice indeed.

I'm not sure what Jell-O sponge might taste like, but the copy says it's the 'aristocrat' among gelatin desserts so it must be mighty fancy.   And the beautiful bowl and berries, very nice.