One of the most important things you can do when preparing to print is to apply print markers, something we’ve blogged about extensively in the last two years.
These markings act as a quality control mechanism and ensure that your output is of the highest standard, free of the kind of mistakes that may undermine an entire project.
Print marks are added within the design stage and used as a guide for both sizing and colouring. Yet despite being an essential part of the overall setup, many are added without a full understanding of their true purpose.
Evans Graphics have set out to plug that knowledge gap. In this article, we’ll explore star targets in more detail.
What is a Star Target?
A Star Target is a print mark test that helps to detect any irregularities in the upcoming work.
Star Targets can expose any errors, astigmatism or aberrations, helping to quickly identify and eliminate unwanted distortions.
Star targets were originally used as photographic resolution targets, only to be adapted in the mid-20th century for use within the printing industry. Here they started as the Lithographic Technical Foundation, which later became GAFT.
Siemens Star
One of the most easily identifiable Star Targets is the Siemens Star or Spoke Target.
The Siemens Star consists of bright ‘spokes’ on a dark background that start in the centre and grow wider as they reach further out, akin to the sunburst pattern commonly used as a background in graphic design.
Because the spokes only meet at the exact centre of the star it can prove a useful tool for comparing printer resolutions. The spokes will appear to touch further away from the centre, where the resolution is limited.
The Siemens Star was developed by Siemens & Halske AG - better known today as Siemens. It emerged in the 1930s and is also used to test resolution for optical instruments and other display devices.
How are Star Targets used?
If there are issues during the print process, such as second contact or movement between press cylinders, the Star Target will not print correctly and will instead show the effects of whatever problem is occurring when attempting to print the work.
The Star Target exaggerates the effect of any distortions including gain, slur, doubling, and paper movement to give a visual indicator that complications exist with the printing process.
The simplicity of the Star Target design makes it easy to pick up on any errors that may occur whilst attempting to print.
Said issues can be caught quickly and ahead of any large print runs… saving valuable expense in the process.
Theirs may not be a starring role, but star targets are fundamental to a successful print project.
