the PDF instruction leaflet about this here.

How to set up white underprint
Flexible Pouches
When printing on our digital press you must be aware that our toner is translucent. (See through).
Printing on a white coloured substrate does not pose any problems but when printing on a clear substrate your design
will appear washed out and if printing on a metallic the CMYK colour will also have a metallic sheen.
If you don’t require translucent (see through) colours you will need to create a white underprint base layer within the
artwork pdf.
This will print as a white flood of toner, printed first onto the substrate followed by CMYK direct onto the top of this.
This guide will show you how to do this using Adobe Illustrator.
This area is to be produced clear
Area of solid colours
Black = Area of white underprint. This underprint helps colours look more opaque.
How to set up white underprint
Flexible Pouches
This layer of white needs to sit ON TOP of the CMYK
layer within the artwork. Don’t worry, the white will
print beneath when printed.
In this example I’m using Adobe Illustrator. I’ve changed the black colour to cyan so I can see what I’m doing.
‘five’ colour swatch
to be set to OVERPRINT
Top Layer
White
Spot White colour
swatch to be called ‘five’
How to set up white underprint
Heat Transfer Labelling
Tips 1 of 2
Watch out for poor fitting white bases.
Make the white underprint is
slightly smaller than the CMYK (trapping)
or you will may get a white line running
around the images.
Not all black or dense colours
need a white base.
For example small black text
does not need a white base.
How to set up white underprint
Flexible Pouches
Tips 2 of 2
File Formats.
Our preferred file format is PDF.
We can accept .ai, .eps, .psd and .ind but be aware these formats sometimes require further supplementary files
for us to print your job perfectly.
We suggest you contact us for further details if you want to use these formats.
COLOURS
All colours used in your artwork should be set as CMYK and spot colours set using the Pantone+ Solid Coated system.
If your files are set up as RGB or using different pantone systems there is a chance the colours will shift and may look
different to what you are expecting.
RICH BLACK
If your design contains large areas of black, it is best practice to build a rich black.
Our preferred rich black mix is C20M20Y20K100 this will give a nice constant dark black.
GREY SCALE
Black and white images look great using our print process but large areas of grey are not recommended.
Try to build greys a percentage of black only to avoid colour casts.
If you follow our advice you should get a great looking label or transfer.
Don’t worry if you do not understand these instructions,
you can always call us for advice we’re happy to help.
01902 365 840