Polyester Plates require less time to generate, and they produce a high end, quality imaged plate, with less labor and material costs. Here are a few basic suggestions that may help to make it work even better for you.

• Set ink form rollers to minimum specifications using the "thin-nest" plate material to set pressures.
• Set dampener form roll pressure to minimum specification. Use ink with the lowest tack that your dampener can handle with-out experiencing ink & water balance problems.
• If you operate Ryobi or Itek Direct Feed Presses that normally use 5 ply, one-piece blankets, change to a 3 ply blanket with a .035" thick Mylar under blanket packer. This combination of a 3-ply blanket and packer has many benefits. It will allow you to set the plate to blanket pressure 30% lighter.
• Plate Clamps must be clean inside the clamping mecha-nisms, and in proper adjustment. Replace worn locking cams and plates. A plate clamp that is in good condition will apply a firm uniform grip on the full width of the plate thus eliminating slippage from either side.
• To test the grip of your clamp, cut a plate into 4 equal strips, and insert them into the plate clamp as if they were a plate. Pull on each strip and compare the grip. If they do not resist the pull equally, call your service company to fix it so that it does.

• If you use a pinbar to hold a punched plate, you should con-sider applying a strip of stick-on reinforcing tape at the lead edge prior to punching. Ideally, a punch should punch holes that match the exact size of the pins of your press pinbar. Holes that are larger than your pins do not hold the plate securely, and the plate will continue to slip lower throughout the press run. Experience has proven that if the pins fit the punched holes securely, a pinbar will hold a punched polyester plate as securely as does any clamp.
• For added run length, and to hold the plate more securely for close register work, apply an adhesive to the back surface of the plate.
• If you use one of the two color presses with locking tail clamps, such as the Ryobi 3302M, preset the tail clamp stops to where they lock up and hold after "only" pulling the plate snug. Trim the plates so that there is no excess plate material. If for some reason you still experience consistent plate stretching problems with any of the 3302M, 3985, 9985 model presses, Ryobi offers a spring-loaded, paper tail clamp kit. It looks and works much like the tail clamps used on the smaller single color models, and it will not stretch Polyester plates.

Good Printing - Roger J. Barker.

This Tech Tip was edited, a full version [was] at www.presssavers.com/we have answers/CTP 101:Press Tips For Using Polyester Plates. Many thanks to Roger Barker.