When it comes to offset printing machines, offset blanket height is a crucial measurement. Imperfection in this particular aspect means total print loss. For any pressman, a wrong blanket height is a cardinal sin. If you are inexperienced with printers, it is imperative you acquire the skill to achieve proper blanket height. In case you are a seasoned hand in printing, do go over a few factors prior to starting a commercial print run.

Offset blanket height fresh from the factory 

This recommendation is applicable solely for brand new offset printing machines. Once the machine is assembled on the floor, check height on all the four corners. Variations should not be more than 1.5 percent. Call the seller or the manufacturer if it is more than this percentage. Any good company will take these blankets back. Ensure the same defective pieces are not re-sent. 

Do note that variations may occur if you do not properly store the blankets. It is crucial that you store offset sheets in a proper manner. The blankets must be stored standing up and in a rolled condition. It should not lie flat. The blanket must be kept in a cool and dark place. 

Blanket on press 

It can be hard to measure height when the cylinder is covered by the blanket. You can measure this by two methods. The first technique is to put a little pinprick into that specific blanket you want to measure. The distance between cylinder and offset blanket surface gets known once the pin contacts the cylinder. One big problem with this specific technique is that the blanket gets punctured. Another (and better) method is to use a gauge which measures the bearer height and then compares the number to offset blanket. The second method is obviously the more sophisticated one. 

Blanket height maintenance 

Blankets must be changed after a certain number of impressions. Most presses do so post 10 million impressions. A few presses do so after 16 million. You should change it after the blanket just loses its excellent dot reproduction characteristics. Every blanket must meet all the necessary ISO standards. Do not over-torque the blankets. Doing so will reduce its height. Position the blanket in such a way that it sits snugly on the complete surface of the cylinder. The material must not move. Do follow manufacturer recommendations on this subject. Premature rips are a possibility if you over-tighten the blanket.