We're making our first full size pvc figure for my Michael Myers costume. After thinking a lot about it I decided the cheapest way to fill out the costume inside would be to use crumpled newspapers in kitchen trash bags and tape it onto it and shape it with the tape as well. What do the rest of you guys use? I figure this way I can throw away the stuff and just store the pvc until next year as well.
I had a problem with the newspaper. It tended to clump after a little bit, and settle where I didn't want it to settle. Plastic grocery bags work really well; and we fortify it with foam or old rags. It just seems to hold up better.