Material for flange mould

Hi, my name is Natan. I’m from spain and work as a carbon fiber machiner for koenigsegg parts.

I wanted to ask what material you use to create the mold flange. I am manufacturing a fiberglass mold and I do not know what material to use that is flexible and suits well. I have seen that you use aluminum tape but what else?

Thank you very much. This is the piece I want to make.

Thank you for the reply I will be purchasing a copy as soon as I get back from work, looking forward to that Mac version