To hold polyester plates in secure register at the Master Cylinder, use a fine mist of Elmers’ Spray Adhesive on the back side of each plate. This will add significant grip-shear-strength between the plate and cylinder surface and reduce stress at the clamp or pinbar. Elmers’ Spray Adhesive cleans from the plate cylinder with press wash and is available from most Ace Hardware Stores for around $5.00 a can.
If you use the pinbar to hold polyester plates, buy a New Pinbar Register Punch from Duarte Register Systems. Duartes’ Pinbar Register Punch cuts tight fitting (press-fit) under-size attachment holes which are designed for specific use with polyester plates.
Under-size attachment holes produce a ‘forced-press-fit’ that causes the plate material around each attachment hole to become thicker and stronger that the plate its self!
This press-fit attachment (I call it the polygrip) developes a grip to the pinbar that is so strong and secure, it does not stretch! If you really want to register polyester plates on a pinbar press, use the Duarte Register Punch and Elmers’ Spray Adhesive!