How to Choose the Right Offset Printing Ink for Paper Types

Offset ink dries through a combination of penetration/absorption and oxidative film formation (UV inks cure by photopolymerization). The absorbency of the paper determines which mechanism dominates:

• Coated paper has low absorbency → relies on oxidative film formation → use a high-gloss oxidative-drying ink;

• Uncoated paper has high absorbency → relies on penetration → use a quick-setting (Quickset) ink;

• Metallic board and synthetic paper are almost non-absorbent → UV curing is mandatory.

  
  

  

Using one ink for every paper — the most common cost-driven shortcut, and the main cause of quality variation;

Overdosing drier on uncoated paper — it easily causes ink emulsification and plate piling, and actually makes things worse;

Looking only at unit price and ignoring post-press compatibility — lamination, hot foiling and UV varnishing all impose specific requirements on the ink;

Choosing ink by habit and skipping proofing — with specialty papers, absorbency can differ with grain direction even within the same batch.

1. Check the paper: absorbency, surface strength, brightness and grain direction;

2. Set the drying route: oxidation / penetration / UV, and confirm post-press compatibility at the same time;

3. Proof and verify: check solid density, dot gain, drying time and rub resistance.