You MUST calibrate your monitor! How? Click here
Create your work in CMYK mode preferably using one of the Euroscale Sheet Fed, FOGRA or US Sheet Fed sets of colour profiles.
For ordinary black text use 100% K not a 4-colour mix.
For shades of grey use a percentage of K not a 4-colour mix.
To prevent large black areas from looking muddy or dark grey (particularly on uncoated papers) use a mix of 100% K + 50% C. This also applies to headlines using fonts over 36 point.
Alternatively use Rich Black (30% C, 30% M, 30% Y, 100% K) but this isn't recommended for ordinary body text or if you intend using small reversed 'white out' text on a coloured background.
If you're using your own colour palette for vector graphics please keep the CMYK breakdown to no more than 300% (when all the colour percentages are added together). The more ink, the less chance it has to dry and the greater the risk it may spread, scuff and rub off.
If you're not sure about a colour mix a good option would be to use only Pantone colours (or any professional colour palette for that matter) and convert them to CMYK prior to output - because the CMYK breakdowns of these colours are designed for high-end printing.
White text and graphics (reversed out)
It is strongly recommended that you do not use small light coloured text and graphics over a background colour or image.
10pt text should be considered as a minimum size when using a light colour - and very thin fonts should be avoided entirely. While they'll still print - you'll be disappointed with the result.
What happens is that all printing presses have a small amount of movement in the positioning of the different colours (the cyan, magenta, yellow and black portions of the print don't line up exactly) so the results can look slightly blurred.
Using a colour mix on small text and fine lines should be avoided for the same reason.
Depending on your software you can create tints of any colour from 1-99% and they'll be visible on a calibrated monitor - but when printed you will be disappointed.
Any tints below 5% will be too light to see when printed on paper - and any tints above 95% will just look like a solid colour. So a practical range for tints is between 8% and 92% when printed on a modern litho printing press.
If you intend to print digitally then a range of between 15% and 85% is more realistic.
Choice of paper will affect the colour of your work
Full colour (CMYK or 4-colour process) printing uses transparent 'process' inks - so be aware that the type of paper will affect the overall print density and colour balance of the finished work. There can be a particularly marked difference between coated 'art' papers and uncoated 'bond' type papers.
Produce your work in CMYK mode preferably using one of the Euroscale Sheet Fed, FOGRA or US Sheet Fed sets of colour profiles.
more information about CMYK printing visit Wikipedia - click