Gilsonite in Printing Inks: Why Ink Makers Use It

Gilsonite has been used in black printing inks for more than a century. It is especially common in news inks and other black offset inks, where it acts as a low-cost resin and colour booster.

What gilsonite does in ink

• Deepens black colour and improves jetness
• Wets carbon black pigment, helping dispersion
• Improves flow and runability on the press
• Reduces misting and improves ink–water balance
• Lowers cost by partly replacing more expensive resins

How it is used

Gilsonite is usually dissolved in mineral oil or vegetable oil to make a varnish. This varnish is then combined with carbon black and other resins to make the ink.

Typical grades

Low-ash, fine ink grade gilsonite with good solubility is preferred. Softening point affects varnish viscosity.

Ink types

• Coldset news inks
• Black heatset inks
• Letterpress and flexographic blacks
• Carbon paper and specialty inks

Typical black ink composition

Selecting gilsonite for ink

• Low ash to protect rollers and plates
• High solubility for clean, filterable varnish
• Consistent softening point for stable viscosity

Benefits for printers

Stronger black at the same pigment level, cleaner printing, less misting and good stability on press.

Read making gilsonite ink varnish and see micronized gilsonite.