To the average person, both heatset and coldset processes may produce the same product and look exactly the same. The difference lies in the process with which they were produced. The essential difference with heatset is that it has the potential to produce much higher quality. Let’s explore the difference between these two forms of offset printing . Coldset Printing Many newspaper printers nowadays use the coldset form of printing. This basically means that they do not apply any heat to the ink to make it dry. It dries primarily through absorption into the paper and evaporation into the air. Ever get dirty hands from handling a newspaper? Sometimes ink will rub off on your hands. That’s coldest. The oils in the ink never completely dry – hence the smell and scuff from newspapers. Heatset Printing Many heatset printers also print newspapers. But in addition, they also print flyers, glossy magazines and other high quality work. This is because the process allows

In my experience, the offset blanket height is the most critical measurement in the printing unit. Printing is doable if the rollers settings are a little off, or if the ink fountain is not calibrated perfectly. But perfection is required with offset blanket height. If it's off, your life will be miserable, and I don't know about you, but as a pressman, there is already enough misery in offset printing . Here are some tips that will help you, the pressman, maintain a proper offset blanket height on your press. This of course assumes that you already know how to achieve the proper blanket height and you are simply looking for the best way to maintain it. Here are some things to watch for. Factory Offset Blanket Height Immediately upon arrival from the factory, check the height on all four corners. It is acceptable to have some variation, but not much. In my experience, if there is a variation of more than 1.5% on any corner I inform the manufacturer. A good offse

Most printing presses do not have them. Yet some see the importance of having ink agitators in every fountain of their press. What reasons necessitate purchasing ink agitators, and are they really beneficial to a pressman. What is the purpose of an ink agitator? Quite simply, inks tend to back away from the fountain roller, causing the fountain to run out. This usually happens undetectable to the automatic ink leveler and so the result is that the fountain runs out. This in turns leads to waste. Plain and simple. An ink agitator usually consists of a cone that continuously revolves, or simple a blade that moves back and forth across the ink fountain. Why are ink agitators necessary? Though their application fits into many types of  offset printing , ink agitators tend to be used by offset printers. The reason for this is because many offset inks tend to be very thixotropic. In other words, they are viscous. Some will only use them in a certain color, for example yellow, which t

If any press is to run successfully, it needs a good preventative maintenance program. Some pressmen rely on outside companies or other departments to do their maintenance, but most take it upon themselves. Each press is different, but if the pressman needs somewhere to start, here is a good place. I itemize each point according to it’s order on an offset heatset web press, but the principle of it can apply to nearly any offset printing maintenance program. Here goes: Rollstand and Infeed Maintenance There are of course different types such as zero-speed and flying pasters , but the principles are the same. 1. Clean all idler and festoon rollers. These tend to build up with tape from the splices. Spend the time to get these very clean. 2. Lubricate well. A good pressman will consult the operators manual and isolate all the grease point. In addition, especially on a zero speed splicer, there are various chains to lubricate. 3. Clean all photo electric eyes for web gui