Aleš Lombergar

dont know about chemical etching but you can use a dremel tool with a diamond bit and engrave glass so im sure you could do it to plexiglass too. you can also get a hand engraving tool thats just a very hard pointed stylus, but that would take years if its very big. you could use the matte clear spray and spray it with stencils and masks, creating an etched look with spray paint. they also had a frosted look spray paint you could use on candle jars, but i dont know if Michaels sells that anymore. just give some real art stores a look and surely you will find an idea, good luck.