Printing With Tough Tex
One of the most difficult types of printing jobs in sheetfed offset is printing non-absorbing materials with conventionally drying inks (i.e. without any application of forced drying). However using the right materials and following the right procedure will enable the printer to obtain perfect results in both quality and efficiency.
Practical tips for printing on non-absorbing materials:
- Do not use any additives in the dampening solution, which contain anti-piling elements. Such elements are usely greasy and non-evaporative (e.g. glycerin). They prevent the inks from attaching to the substrate.
- If alcohol is being used in the dampening solution, dosage should be 8 to 12%.
- Ph of the dampening solution should be 4.8 to 5.5.
- Preferably, sheetfed offset machines with separated ink/water units should be used.
- During printing, set water dampening as poor as possible. The more water is used, the longer the drying time will be. In case of less ink image the use of Multidrier (4%)) is recommended (mix through the ink).
- Use only substrates that are suitable for offset printing. We recommend testing this suitability in advance. A simple test is the "fingertip-test"; fingertip a little bit of ink on the substrate; after 4 hours ("open air") the inks should be dry and strongly anchored to the material.
- Choose Tough Tex, a conventionally drying offset ink (drying by oxidation) which is formulated for printing non-absorbing materials in sheet fed offset.
- When using Tough Tex ink, NEVER STOP THE PRINTING MACHINE FOR MORE THEN 30 MINUTES. The ink will start to dry on the rollers and will be very difficult to remove, due to the extremely strong anchoring.
- For extra gloss or protection of the printed result, an oil based overprint varnish can be used.
- Application of spray powder, to avoid setting off, is advisable in normal dosage.
- Clive Harper