Below are some tips from our Technical Hotline staff to help solve common problems that are frequently asked by printers.
Troubleshooting: Marking on Matte Finished Paper
One of the more frequent calls to our Technical Hotline comes from frustrated printers seeking a solution to marking and scuffing on matte coated stock. Often, they wrongly assume that they are experiencing an ink drying problem.
Conductivity and pH Fundamentals
It is important that conductivity and pH levels of dampening solution be optimum and consistent. Printing Industries of America recommends measuring conductivity and pH with every fresh batch of dampening solution and every four hours when the press is running. Readings should be taken in the water pan at each printing unit and in the recirculator. Water pan readings can provide an early warning about potential print problems.
Grain Direction and Folding of Paper
The grain direction of paper is in the direction the web of paper travels through the paper machine (machine direction). Cross grain is referred to as the direction across the web. The strength of the paper is stronger in the machine direction then in the cross grain direction. The machine direction has good dimensional stability due to the manufacturing process. Cross grain also has greater expansion and contraction characteristics resulting in it being less stable.
Offset Printing on Nonabsorptive Surfaces
Offset printing on nonabsorptive surfaces is growing rapidly. Many printers successfully print on nonabsorptive substrates on a regular basis, but it must be done correctly to avoid a disaster.