Digital fabric printing has been used as a tool for sampling new designs for both fashion and furnishing designs for some time, however it’s not been all plain sailing.
A customer would purchase a new design, which would then be colour separated ready for digital printing onto fabric. The colour separations would then be digitally printed by the customer in numerous colour ways and used by the design team to gauge interest before they go to the expense of engraving a set of rotary screens. Also any changes and amendments can be made as screens have not yet been engraved, so this gives the customer that opportunity to fine tune the design and make it correct for the chosen colourays.
So, the design is approved and screens are simply engraved to replicate the digital sample? Well no, this is not the case. If the separations we’re simply engraved they would not be a true representation of the digital sample, due to the fact that during the laser engraving and wet print processes, there is an amount of colour spread.
There are two ways to work around this, one is to devalue the original digital print, to replicate what could be achieved with the rotary printing process and the other is to amend the digital separations after the sample has been produced to allow for laser over burn and colour spread.
The first method, to devalue the print, involves increasing the graph on tonal separations to make tonal separations appear heavier and to expand the solid/flat colours by adding pixels, again to make the separations appear heavier. It may also be necessary to loose some of the fine detail and really low areas of tone that may be just too fine to achieve on a rotary screen.
The second and best way would be to alter the separations once the digital samples have bee produced. This is done by lowering the tonal curve on the tonal separations and pulling back solid and fine areas to allow for the spread during engraving and printing. Many people think that the curve can be altered by applying a standard curve to everything which would then convert a certain percentage to a pre determined figure, but this really doesn’t work. Our artists refer to the digital sample and alter the tonal graph on each individual colour until we feel the graph will allow the engraved screen to match the sample. With the fine details and flat separations we may scale them to a high resolution and take a pixel or two off them until we again feel like the finished engraved screen will match the sample. This takes years and years and years of experience, but the results are excellent. We often take the digital print and the finished print form the rotary screens and compare them and it’s often difficult to tell them apart.
One other important thing to remember is to raster the tonal files before they are digitally printed. It would be easy to print the greytone files and they would look fantastic, but it is impossible to print a greytone file on a rotary screen, so a rastered digital file is a necessity if matching to a rotary print.
So, that’s how to match a digital sample to a rotary screen repeat and get good results.Go back
Meshtex has been involved in the textiles industry since 1972, supplying colour separation services and rotary screen engraving to the fashion, furnishings and wallpaper industries. In 2005, we started to produce printed fabric homeware products and kitchenware products as a … Continue readingDigital Printing on Polyester Fabrics
The dye sublimation process is very clever process, which utilizes the chemical phase transition process called sublimation, whereby a substance is changed directly from a sold phase into a gaseous phase without going through the usual intermediate liquid stage. This … Continue reading