Why Do Blacks Print Differently?
Printers have little control over the colors and tones that will print from a pdf file.
Typically you get what is in your file unless you ask for a global color correction.
If two files are set up differently to print black – the results will print differently. Large black background areas with a grey mix instead of black will print noticeably different.
Also if 2 different output devices are used to print the same file on 2 different types of material, say vinyl and foam core, the results of black will still be significantly different.
Pdf’s from RGB artwork will also print differently than CMYK pdfs. 100% black will not always yield a rich black. A mix of other colors will make the black look better.
Here is an explanation of 3 types of black.
Andrew Kelsall Design writes:
Neutral Rich Black(also known as Rich Black) | C40 M30 Y30 K100 : This type of black is roughly comprised by the preceding color combination, but varies between designers’ personal preference.
Registration Black | C100 M100 Y100 K100 : This mix is comprised of the maximum amount of cyan, magenta, yellow and black.
Flat Black | C0 M0 Y0 K100 : This black is just made up of 100% of the black channel, with no other ink in the mix. Also known as Standard black.
The printer being used will also have an affect on the blacks depending on whether it is a 4/C or 6/C printer. The material being printed can also have an effect too.
PDF’s saved differently or being saved using 2 different versions of Acrobat can print differently
Quick low-cost print jobs with no lead-time do not afford the luxury of printing proofs for checking these things prior to the final run. Make sure you have set up your files correctly and communicate with your printer your final expectations.
- How the PDF was saved
- Are the black levels the same on all documents
- Printing on Different media
- Are they being printed as grayscale
- Different Printers, Commercial Press, Ink Jet, Latex, Laser Printer
- File set-up as 100% black, a grey mix or black with a color mix
- Files saved differently
- Reproduced from RGB artwork or CMYK