You can read and confirm the notes in the preflight or you can revise your artwork again.
RGB objectsYour artwork contains images that are structured in RGB. These are converted to CMYK in our workflow. Converted images may differ visually from the original RGB image.
If you want to be on the safe side and know in advance how the images will look after printing, simply convert the RGB colors to CMYK.
Multicolored barcodes
EAN codes, QR codes or similar were created in CMYK. This is not ideal for printing. There is a risk of color flashes. To avoid this, make your codes monochrome.
Low-resolution images/bitmaps
The optimum resolution of images or bitmaps for printing is 300/600 dpi. Make sure that the resolution is not too low. There is a possibility that images or bitmaps will appear pixelated or blurred if the resolution is too low.