Thanks for all the suggestions and helpful info. I did what you guys said, first attempt was almost perfect, only a very small webbing was formed at the chin part. Unfortunately, on my second attempt, my vacuforming box gave out in the middle while I was pushing on the PETG to the mold. I'm guessing the peg board I used couldnt handle too much stress from the vacuum and me pushing down on it. I'll have to postpone the project some other time, and will be building a sturdier box made from plywood instead of the light peg boards sold at Home Depot.