I was told by a signmaker, who also happens to keep snakes, that if the wood was primed then adhesion would be excellent. And I found a zoo in New York or someplace out east that put graphics inside of painted wooden cages. Just use the cheapest paint or primer you have available or can find. However, it does stick well to MDF and melamine.
My biggest concern with vinyl film is finding a caulk that will stick to it. I have not experimented around with this much so let me know if you find anything. My other gripe with it is how glossy it is but I guess you can't have everything.
I got a 30" x 150' roll for about $105 shipped and even got a few squeegees thrown in. But I shopped around a lot.
Regarding brand, just get the cheapest film you can find. More expensive films last longer only in exterior applications. Their extra durability will be neglible in an indoor snake cage and are not worth the money. And the calendared VF is actually thicker than the cast so in one regard you're better off with the cheaper stuff.
Also, get the unpunched film.
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Current snakes:
0.0.1 Gonyosoma oxycephala - Java locale (green)
1.2 Gonyosoma oxycephala - Jave local (green)
2.2 Gonyosoma janseni - Seleyar locale (all black)
1.2 Gonyosoma janseni - Celebes locale (Black & Tan)