vacuum forming alternatives

i have been on this forum and many others, and as the geek i am i am very intrigued as to these costumes and mannequins in your custom home theater or game room. and on this handy-man of a trek i found that one of the processes of making such killer costumes is a process called vacuum -forming. now my question is not a matter of how, but a matter of what? i know there are a few plastic that can be used as plausible formers, but all of THESE "alternatives" seem to be out of my [16 year old,] price range. However i found and feel that plastic found in cheap, household things such as buckets and garbage cans, could actually be plausible plastics. I know the average thickness for a forming plastic is .080, but does any one know an example of a plastic that is this ideal thickness? but what im trying to get at is,.... well has anybody tried this, etc. please any thoughts, feeling, or ideas... please post, well, something. maybe you could find a killer tutorial on Google that i may have skipped over. also anyone know how to make the start of a tusken raider helmet?

well man, as for having worked for a plastics retailer and fabricating shop, just about all forming plastics (therm-form, press form, cast sheet) come in various sizes between gauged thicknesses of as low as .010 up to .200 which in turn can be converted to fraction measurements like up to 3/4 inch.

Now your typical plastics seen for vacuum forming are:
Styrene
ABS
PETG
HDPE
Acrylic
and sintra

All these usually are sold indivdually in a 4' x 8' sheet. Styrene will normally run about $20 a sheet where the prices vary up and down for the others. Your best bet is to find a plastics wholesaler around your area as their orders are usually in the hundreds of sheets in plastics. Look in your yellow pages under "signs". Most sign shops vacciform in some sort, so they probably have those plastics around and you could also ask I they have any flawed scraps big enough for you applications.

Now for the plastics around the home ie: trashcans, storage tubs are usually cast in polypropelene which is liquid die cast, which makes them extremly difficult to near impossible to use in vaccforming.

Along with waht Gilmore said, If a sign shop doesn't use these materials they can usually order them for you cheaper than you can. They'll add a little to their cost, of course, so they at least make a little something. The local sign shops in my area, for example, don't use sintra, etc... but they said they will order it for me any time I need some. Seems that even though you aren't having them make a sign for you they'll try to help out for a potential repeat customer.