hey guys , ive just built a vacuum former ( nothing fancy , just a simple setup ) and tried my first pull last night and ran into a problem , im using 2mm smooth white abs and after its formed , its coming out with textured areas on it , some areas are as smooth as a babies bum and some areas are rough as guts , is my buck causing this , is abs the wrong stuff to use , am i heating it too much or too little , i cant find any info online to help me , so any info you can give me is greatly appreciated .cheers