All printing here is printed in CMYK. We do not print in RGB.
Any files that you use in your designs or any artwork submitted to us in RGB colour spaces will be automatically converted to the CMYK colour space for effective printing.
RGB colours are for screen application only and there are colours in the RGB spectrum that CMYK cannot reach - this is why your designs in RGB will come out slightly different when printed.
CMYK will reduce the brightness of your RGB files by around 10% it may also cause a colour shift or cast - the best workaround to this colour change is to create your artwork in CMYK or convert your images to this format.
Our online design module is set up to work in CMYK as standard and will convert any RGB file used within it.