How can I make sure my blues do not come out purple?

When using a blue in your design, always make sure to leave at least a 30% difference in your Cyan and Magenta values.

100% C 100% M 0% Y 0% K

Blue is close to purple in the CMYK spectrum. Remember, use a low amount of magenta whenever using high amounts of cyan to avoid purple.

EXAMPLE: C-100 M-70 Y-0 K-0