Glad to be here!
I have started working with composites just recently and looking to add it to my Industrial Design Portfolio.

I have one question to start off with. What is the best material to use as a plug to laminate a simple carbon fibre plate through vacuum infusion? I have tried acrylic and aluminum. However, it never comes out with a clear and clean look.

I would appreciate any suggestions.

Thank you

Its hard to tell in photos but it could be slight marring on the mould surface, a slight witness mark from the release agent?  How was the release? did it come off easily?  Sometimes on thin sheets, if the release is a bit tougher than usual, as you peel the sheet off you can get the beginning of stress fractures or cracks where it flexes a little too much and that can look like that before it becomes proper visual cracks if flexed even further. 

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant