Have you ever wondered why we need to use different screen angles in flexography? First of all we need to remember that we consider the screen angles when we look at the final printed product, so the parameters we set in the prepress/imaging workflow are meant to obtain the angles as described. Then we need […]
Screen angles in flexography Read More »
The information about the size (typically the diameter) of the minimum isolated dot refers to the characteristics of the plate and it is normally completed with the term positive and/or negative. Example: Minimum positive isolated dot: 100 µm Minimum negative isolated dot: 50 µm The minimum isolated dot size indicates what is the ability of
What does “isolated dot” mean? Read More »
Description Causes Remedies Description Slur is characterised by the smearing of the printed image: the dots are distorted in printing direction, typically elongated, and exhibit an oval shape. This condition is caused by slippage at the point of contact and impression between the plate and the substrate and/or even the plate and the anilox roll.
Slur: the sneaky enemy of print quality Read More »
It is important to know in depth the technical characteristics of the printing press, and especially the configuration of the cylinders. Their diameters, combined with the gauge and the resilience of the plate, of the mounting tape and of the substrate, will determine whether the print will happen in the right position, without slurring, having
Where does print happen? Read More »
Description Causes Remedies Description With the term “ghosting” we describe the presence of a faint image of a design that shows in areas where it was not intended to appear. Usually it is a repeated pattern on print along machine direction. Causes The main cause is attributable to the failure of replenishing, with fresh ink, the
The information about minimum dot indicates what is the size of the minimum printing dot that appears on the plate. This size is normally expressed in microns (µm), or, less commonly, as a percentage of a given linescreen, and it is set as a threshold in plate imaging to obtain such size on the finished
What does “minimum dot” mean? Read More »
I recently came across an interesting video that was published by one anilox rolls manufacturer that, in the attempt of promoting their technology, depicts dot dipping as an industry myth and illustrates flexo users, who believe that this problem exists, as troglodytes… “The industry myth that dot dipping is occurring within the anilox cells is impossible. Physics
Do you really think that dot dipping doesn’t exist? Read More »
Can you recognise the cause of dirty printing in highlights?It is important to understand wether the issue is related to dot dipping, thus plate-to-anilox ratio, wrong metering of the anilox surface or other causes.What is visible on the printed product is a generally a dirty aspect that forces to repeated stops for plate cleaning and
Dirty highlights: dot dipping or ink spitting? Read More »
Ink transfer efficiency, ink coverage, color density, color matching and overall print quality strongly depend on properly maintained and clean anilox rolls.Check your anilox rolls thoroughly with proper high magnification viewing tools to ensure that your cleaning operations were effective.
Can you see how dirty is your anilox roll? Read More »
Description Causes Remedies Description Dots in midtones screened areas, that normally should appear separated on printing, bridge together causing a dirty aspect on printed product. Causes Main addressable cause is anilox volume too high for the selected plate linescreen, or, viceversa, plate linescreen too high for the available anilox volume. The ink, collected by the printing
