On my first try to produce a composite part a came across this unexpected issue .I 3d printed a fork core for a bike frame i wrapped the core to CF and then vacuum bag it.But when i measured the dried part the fork legs were closer(25mm-1') they previously were !!!
here my photos 

why this happened ?How can i over come it ?Should i alter my design in order to compensate for the shrinkage ?Should i build a support to hold the fork legs in the vacuum bag ?Thanks in advance!

Thank all of you so much for your fast and though insight , this is such a good place to be and learn, i spend quite a time here reading
As you may see from my picture i have bought and use a  tubular  vacuum bag  460 mm wide  . Since these consumables need some processing time and are not readily available to the place i live the faster way to get a bigger bag is to slice open the bag i have and connect two pieces .It would be rally easier for me to see a picture of a big bag with wriggles in order to understand how to strategically place my item in the bag.Sorry but i have zero experience . 

Unless I'm looking at your pic really funny you have your job across the bag ???
Just run your job along the bag an cut your bag a lot longer