When submitting files for printing, there are a number of important points to keep in mind. Below are a number of indications for a process that is as smooth as possible. If you are not sure about the feasibility of your print, you can always email for advice.
Save in b&w as PDF 1.4 without layers and name the color of the layer in the file name
Up to 180% ink coverage
Up to 4 colors per side
Use trapping to avoid white gaps between color layers
Convert text to letter outlines
Crop marks within the printable area of 3mm bleed at crop marks
Maximum print area: A4 277 x 190 mm and A3 407 x 287 mm; a margin of at least 5mm all around from the edge