latex batman cowl - a Q about countering shrinkage

cross posted on the BOTB, but was wondering if I could get more opinions on here

was reading about sculpting and then casting a Bat cowl in latex. Read a few threads there that in order to counter the inherent shrinkage of latex (not latex foam or polyurethane rubber) - that some suggest added quite a bit added to the initial bust.

one of the more detailed accounts suggests:

- use a bigger bust - eg 24 inch circumference noggin, use a bust that is 26 inch
- add almost an inch of clay on top of that

was wondering though, cos most of the WIPs I see - the sculpt on top of the bust doesnt look that thick?

what I hope to work with is a cheapo duct tape life cast of my head. build up the extra inches to the circumference with card board. whack some clay on top of it and start (try) sculpting.

any suggestions/opinions/previous experience welcomed pls!

- S

a good quality latex will shrink about 10% so if you do the math, you can calculate the extra size needed and sculpt accordingly

thanks fettster - thats what I meant though.

based on simple math; it seems like 26 inch bust + a bit more of clay (ie not as much as 1 inch) eg 26.5 inches (circumference).

Reducing those estimates by 10%; 26.5 - 2.7 = 23.8 inches (ish)

seems right, but the sculpts that I have seen - the clay doesnt look that thick; mind you this is just by pictures in the exposed areas eg round the eyes, round the mouth.

just wondering how to reconcile the difference? Guess I will have to go experiment and see

thanks

- S