How to Mix Pad Printing Ink

Mixing Ink the Right Way

by Pete Baxer

In this section, we will discuss ink mixing – a basic but very important step to achieve a quality print. If it is not done properly, the entire printing process can get very frustrating and, in turn, may cause a loss of production and a waste of valuable time and energy.

Before you start, it is essential that you use the proper equipment. Unlined mixing cups (no wax), mixing sticks and a quality electronic scale with an accuracy of .1 grams are all very important. Without these items, ink mixing becomes guesswork, causing the quality and precision of the print to suffer.

Step by Step Ink Mixing:

1. Zero or tare out the scale (make sure it is on a level surface).
2. Add the ink to a mixing cup. Try not to use less than 40 grams as it will not flow well in the cup or inkwell once mixed.
3. Add appropriate hardener ratio. For 1000H, depending on the ink series, the ratio is 4:1 or 10:1 (4 parts of ink to 1 part of hardener or 10 parts of ink to 1 part of hardener). For HGL, the ratio is 20:1 (20 parts of ink to 1 part of hardener).
4. Mix these two ingredients completely. Note: inks that are activated with hardener 1000H/1000KGL have a pot life of about 8-10 hours.
5. Begin adding solvent at a ratio of about 5%-10% then re-mix.
6. Continue to add solvent at a “drop by drop” rate until a working viscosity is achieved. Adding all the solvent at once tends to “shock” the ink. Typical mixing ratios are 15% solvent to the weight of the ink. Remember, it is easier to add than to take away. This also helps to prevent ink from over thinning.

Please note that Sapphire® Inks are highly opaque and take more solvent than most inks. The adjustment of the viscosity of the ink depends on the quality of thinner that is being added. Generally you should never exceed 20-25%; however, dilution varies from series to series.

If you follow these simple steps it should help to improve your printing process. If you ever have any questions please contact me, Pete, at Inkcups and I will be glad to help you.

Pete Baxer graduated from…
the Harvard School of Ink with a degree in Ink Mixing.
Before joining ICN, Pete worked as a production manager for a
promotional products company for 8 years.