Tech Tips

Basic Colour Matching – The Colour Wheel

Printers often wonder why a colour matcher will select certain pigments or colour toners to formulate their colour.

There are many reasons to use a particular pigment, including weather or chemical resistance, fade resistance, or even price. All of these constrain the ink technician, but, once the colour pallet has been set by the end-use requirements, the matcher will use the principle of the Colour Wheel to match the colour.

Surface Tension and Printing on Film

All film printers have, from time to time, encountered printability problems such as pinholing, poor adhesion or lack of colour strength. Very often, upon contacting their ink supplier, they are confronted by the question, "What is the treatment level of your film?"

The treatment level, or Dyne level, or, more precisely, the surface tension of the substrate has a strong influence over the quality and durability of the printed film.

CIE-lab system (LHC)data interpretation

L: Lightness (Color strength)
- Positive: Weak
- Negative: Strong

C: Chromacity (saturation or dirtiness of the color)
- Positive: Clean
- Negative: Dirty

H: Hue (Color shade)
- Positive or negative difference depending on the selected color region.
(Refer to the chromacity circle)

Ink Recycling

The recycling of inks often appears as being a necessary evil, an arduous solution to an expensive problem; that of an expanding ink inventory. Even though it's true that conventional solutions are demanding in skills and time, there are means that can greatly simplify the life of an ink technician. The problem of an run away ink inventory is too often attempted to be resolved with a single approach. It is usually a good practice to identify multiple rework methods to to assure the recovery of as much ink as possible.

Harper Hand Proofers

These technical tips are in regard to the use of the following bladed Harper handproofer models: Junior Echocell and Phantom.

PREPARATION:

First, you need to cut a piece of substrate that is slightly larger than the width of your handproofer and one and a half the length of the instrument. Apply the substrate on the surface of your work table with the help of an adhesive tape. Then, assemble your instrument with the doctor blade and the appropriate anilox for the job by making sure to apply all necessary pressures.

There are a number of causes why a photopolymer printing plate can show signs of swelling, cracking & orange peel after only running for a few hours on press

1. Typically a polymer plate will start to show signs of ozone cracking if the printing plant is extruding film &/or ozone levels are very high.( typically in poor ventilated environments where there are many extruder along side the printing presses).