I am looking for an alternative to resin to fill a series of jars with, that will harden solid.
My aim is to make it appear as if the jars are filled with an opaque liquid that could pass for some kind of generic produce at a distance (milk, jam, table sauce, etc.).
I intend to put a tube in the center of each jar to create a chamber, and then fill the space between it and the side of the jar with "something" colored to make the jar seem full, so that you can take the lid off of the jar and put a model or miniature diorama inside and let it be hidden until the lid is taken off (For example, a jar of honey containing a model of a bee).
The normal go-to for this is epoxy resin, but I don't have the budget or ventilation required to use resin on this scale (and it's far too messy), so I'm looking for a cheaper and safer alternative, like a plaster compound or something.
It needs to be non-toxic, set solid, and to be able to be colored so that it's opaque, but does not need to be particularly durable.
I have considered simply painting the inside of the jars but it just looked like a flat surface and didn't have that slightly translucent look that you would get with a liquid that you can achieve with resin.