WHAT IS THE DIFFERENCE BETWEEN VELLUM AND TRANSPARENCY PAPER YOU ASK?  I CAN HELP YOU WITH THAT.

TRANSPARENCY PAPER IS PAPER USUALLY USED FOR TRANFERING AN IMAGE EITHER WITH A PROJECTOR OR BY EXPOSING THE IT TO PHOTO EMULSION IN THE SILK SCREENING PROCESS FOR THINGS SUCH AS T-SHIRTS, ETC.

THERE ARE TWO COMMON TYPES OF TRANSPARENCIES. THE FIRST IS TRANSPARENCY PAPER AND THE SECOND IS VELLUM (ALSO A TRANSPARENCY PAPER).

REGULAR TRANSPARENCY PAPER IS A 100% CLEAR TRANSPARENCY THAT WHEN YOU LOOK THROUGH IT IT'S AS IF YOU WERE LOOKING THROUGH A PIECE OF GLASS WITH NO BLOCKAGE OF LIGHT.

VELLUM PAPER IS A FROSTY LOOKING PAPER THAT IS VERY SEMI-TRANSPARENT ONLY ALLOW YOU TO BE ABLE TO SEE ABOUT 50% OF THE LIGHT THAT CLEAR TRANSPARENCY DOES.  WHEN AN IMAGE IS PRINTED ON IT HOWEVER YOU CAN SEE THE IMAGE ON BOTH SIDES.

THE MAIN DIFFERENCE IN THE TWO IS THAT VELLUM WAS CREATED AS A MUCH CHEAPER ALTERNATIVE TO CLEAR TRANSPARENCY ESPECIALLY WHEN USED IN THE SCREEN PRINTING INDUSTRY.  THE COST OF VELLUM PER SHEET IS ROUGHLY HALF THAT OF CLEAR TRANSPARENCY. AND WHEN IT COMES TO MAKING POSITIVES FOR EXPOSURE FOR SILK SCREEN PRINTING THE COSTS FOR THESE IMAGES CAN REALLY ADD UP WHEN YOU FACTOR IN A SINGLE PRINT SHOP DOING HUNDREDS OF DESIGNS PER YEAR.