Coldset printing is a web offset process in which ink sets mainly by absorption of its liquid components into porous paper, without a heatset drying oven. It is commonly used for newspapers and other publications printed on absorbent, uncoated stock.
“Coldset” describes how the ink sets. It does not mean refrigerated printing, and it does not mean that a press produces no heat.
Jump to: How it works · Coldset vs heatset · Ink rub-off · Common questions
How does coldset printing work?
A web press prints onto a continuous roll of paper. In offset printing, the plate transfers the inked image to a rubber blanket, which transfers it to the paper. Coldset changes the ink-setting system, not that basic offset transfer.
Absorbent paper takes up liquid components of the ink, leaving the printed image at the surface. The web does not need the heatset oven-and-chill-roll sequence before folding.
This is why newsprint is a familiar coldset substrate. Paper absorbency and the ink formulation must work together; coated stock cannot simply be substituted on the assumption that it will set in the same way.
What is coldset printing used for?
Newspapers are its best-known application. It also suits some newspaper-style advertising and other publications where absorbent stock meets the job requirements. A newspaper format alone does not prove that a product was coldset printed.
Coldset vs heatset printing
| Feature | Coldset | Heatset |
|---|---|---|
| Ink setting | Mainly absorption into paper | Heated solvent evaporation followed by cooling |
| Drying equipment | No heatset oven required | Dryer and chill rolls |
| Typical paper | Absorbent, uncoated stock such as newsprint | Coated or uncoated stock suited to the system |
| Familiar products | Newspapers | Magazines, catalogues and advertising inserts |
Heatset uses a dryer to evaporate ink solvents, then chill rolls cool the web and help set the remaining ink film. Cooling is important, but it does not make heatset “really coldset”: the complete process includes both stages.
Omitting the heatset drying system can avoid its equipment and energy requirements. That does not establish a universal cost saving per copy; paper, run length, coverage and production requirements also matter.
Why can newspaper ink rub off on your hands?
Coldset prints can transfer colour when rubbed. Rub-off is not proof that every copy has failed to set, nor does it tell you that the ink must keep drying for a fixed number of days or weeks.
Sun Chemical’s coldset troubleshooting guide identifies factors including excessive ink film, ink properties, paper absorbency and fountain-solution conditions. Diagnose the ink–paper–press combination rather than assuming that more waiting will solve the problem.
If rub-off is excessive, compare the job with your density targets and approved materials, record when it occurs, and discuss the observations with your ink and paper suppliers. Follow their specifications when making changes.
Common questions about coldset printing
Is coldset the same as offset printing?
No. Offset describes the image transfer through a blanket. Coldset describes one ink-setting approach used in web offset printing. Heatset is another.
Does coldset depend on heat to dry the ink?
Conventional coldset primarily relies on absorption, not forced solvent evaporation in a heatset oven. The absence of that oven is the useful distinction.
Can smell or paper gloss identify the process?
They may suggest a process, but neither is a dependable test by itself. Use the printer’s production information when you need a definite answer.
Technical references
- Sun Chemical technical background on ink setting and rub resistance (patent description).
- Contiweb: web offset drying and chilling equipment.
- Sun Chemical: coldset rub-off troubleshooting.
Reviewed October 2026: The explanation of coldset ink setting was corrected, the heatset comparison clarified and the original three photographs retained.
Explore more practical printing articles at The Offset Pressman.
Thanks for the brief.
ReplyDeleteStunning resourse. Many thanks.
ReplyDeleteNice post thank you Mike
ReplyDelete