What is Web Press Printing?

When it comes to commercial printing, the kind of print you’ll choose will depend on a few factors. One common solution is web press printing. 

Businesses typically use a web press for very high-volume printing; think magazines, catalogs and newspapers. However, you can also choose web for direct materials like technical publication printing – instructions and user manuals.

Web presses typically run much faster than most sheet-fed presses. Also, printing presses for flexographic printing, often used for packaging, are usually web presses.

How Does a Web Press Work?

A web press processes the printing on a roll before it is cut. Picture old movies where newspapers are running along huge metal drums – that’s a web press. 

Once printed on, pages are separated and cut to size then put together into the finished product like mass-market books, magazines, newspapers, catalogs and brochures. Someone looking for runs of printed material in excess of 10,000 or 20,000 impressions typically choose the web press option.

Speed is a determining factor when considering the completion time for press production; some web presses print at speeds of 3,000 feet (915 meters) per minute or faster. In addition to the benefits of speed and quick completion, some web presses have the inline ability to cut, perforate, and fold.

Web presses are divided into two general classes: coldset (or non-heatset) and heatset offset web presses. The difference between the two are how the inks dry. Cold web offset printing dries through absorption into the paper, while heatset utilizes drying lamps or heaters to cure or “set” the inks.

Heatset presses can print on both coated (slick) and uncoated papers, while coldset presses are restricted to uncoated paper stock, such as newsprint. Some coldset web presses can be fitted with heat dryers, or ultraviolet lamps (for use with UV-curing inks), thus enabling a newspaper press to print color pages heatset and black & white pages coldset.

Heatset Web Offset

This subset of web offset printing uses inks which dry by evaporation in a dryer typically positioned just after the printing units. You’ll see this typically done on coated papers, where the ink stays largely on the surface, giving it a glossy high contrast print image after the drying. As the paper leaves the dryer too hot for the folding and cutting that are typically downstream procedures, a set of “chill rolls” positioned after the dryer lowers the paper temperature and sets the ink.

The speed at which the ink dries is a function of dryer temperature and length of time the paper is exposed to this temperature. This type of printing is typically used for magazines, catalogs, inserts, and other medium-to-high volume, medium-to-high quality production runs.

Coldset Web Offset

Another subset of web printing, coldset web offset, typically gets used for “not pretty” print output; think newspaper production or user manuals.

In this process, the ink dries by absorption into the underlying paper. A typical coldset configuration is often a series of vertically arranged print units and peripherals.

Web Press vs. Sheet Fed Printing

When comparing web press to sheet fed, consider the pros and cons of each capability. Sheet-fed presses offer certain advantages. Because individual sheets are fed through, a large number of sheet sizes and format sizes can be run through the same press.

In addition, waste sheets can be used for make-ready (which is the testing process to ensure a quality print run). This allows for lower cost preparation so that good paper is not wasted while setting up the press, for plates and inks. Waste sheets do bring some disadvantages as often there are dust and offset powder particles that transfer on to the blankets and plate cylinders, creating imperfections on the printed sheet. This method produces the highest quality images.

Web print presses, on the other hand, are much faster than sheet-fed presses, with speeds in excess of 20,000 impressions or 80,000 cut-offs per hour (a cut-off is the paper that has been cut off a reel or web on the press; the length of each sheet is equal to the cylinder’s circumference). The speed of web-fed presses makes them ideal for large runs. However, web-fed presses have a fixed cut-off, unlike rotogravure or flexographic presses, which are variable.

If your head is spinning and you’d like to ask questions, leave them in the comments below or set up a consultation. We’re happy to walk you through your business’s needs and your options.