Reading over some forum topics it seems that the sealing of bagging material to flanges causes a lot of problems?
If a piece is small enough then would putting the mould in a bag not be a better solution then there is only one seal to make at the bag mouth - which should be much easier than trying to tape onto a mould which might also not be 100% airtight?
Added advantage is then that you don't need a mould with a flange?

What don't I understand?