Hi this is Praveen.
I'm a printing technology student.
My question is
1. Is it possible in printing with RGB color inks.?? i mean not bromide printing which uses light theory.
2. Does a mixture of Red, Green, Blue inks produce white?? as in additive theory the mixture of RGB light produce white colour.
pls clarify me.
rgb only refers to viewing light...the only combination of rgb inks that would look white would be none of each! RGB prints work like transparencies, with more or less light of each colour allowed through. You either view the light passing through a film or passing through layered filters and bouncing off a reflective substrate underneath.
With inks there is no (practical) way you could mix red and green to make yellow for instance, but with light, red and green does make yellow.
To clarify, have a look at the difference between additive and subtractive primaries. Cyan is sometimes called 'minus red' as it is an ink that absorbs red and reflects blue and green. Conversely, if you have a red filter, light passing through loses its green and blue wavelengths but lets the red light through to be viewed, just like the red ink reflects red light but the problem is that red ink cannot reflect enough to make all the necessary colours and if a colour was made of a mixture of colours, the overlapping inks would block each other out.
Some systems use rgb dyes but have transparent inks with reflective substrates or thin stripes of colour and limited range of colour.