What is the full form of cmyk in adobe Photoshop?

Answer 1

CMYK is a colorspace used in printing on an inkjet printer or a printing press

C - Cyan

M - Magenta

Y - Yellow

K - Black, which uses the letter K because old-time printers called black "key."

And for extra fun, where the pigments in traditional inks used to come from:

K: Black ink is colored with carbon black. Ink used to be more expensive in the summertime because we got our carbon black from tire companies, they can only make so much of it and in the summer they were using most of it to make tires. An ink company finally decided to build a carbon black machine, and now ink is the same price all year round.

M: Magenta pigment came from the scale of a little bug called "cochineal."

C: The reason it's called CYAN is it was made out of CYANide gas. They bubbled hydrogen cyanide gas through water then up through glass tubes, and from there into ammonia that would neutralize it. The gas would deposit a blue material called Prussian Blue on the inside of the tubes. After enough was there, they would turn off the gas and wash out the tubes.

Y: Yellow pigment was made out of lead. The pigment in the paint they use to put the yellow stripes on the road is still made out of lead.

Now we use Azo dyes to get us to the same place, and you could almost put ink on bread and eat it.

Answer 2

C= cyan

m=magenta

y=yellow

k=black