Adobe Photoshop CC
Shift from RGB to CMYK photoshop pulls it to the nearest line, this makes it look duller.
Why don't we always work in CMYK?
The default mode photoshop works in is RGB, some features can only be applied if in RGB mode. When you work with CMYK files they are much larger.
Gamut
Grey areas show where the colours are not printable and will be printed different colours. If we convert to CMYK Photoshop will pull those colours to make it printable.
Adjusting the hue/saturation, brightness/contrast, levels etc it will get rid of the grey gamut and lets you adjust the image to see what its will look like when it comes to print. If you don't adjust this the colours will print out differently to what you see on screen.
Proof colours - Shows how the image will look when you convert to CMYK but the mode is still in RGB.
Work in RGB mode until you finish editing you image. Then convert the image to CMYK mode and make any additional colour and tonal adjustments. Especially check the highlights and shadows of the image. Use Levels, Curves, Or Hue/Saturation adjustments layers to make corrections. These adjustments should be very minor flatten the file if necessary, then send the CMYK file to the professional printer.
Holding down alt and clicking on the swatches on photoshop will delete the swatch. Save the swatches with one colour (black) so you have an empty swatch palette for the future.
Replacing swatches lets you load any other swatches that you might have saved, including the 'empty swatch'.
Top box with triangle means the colour is not printable, by clicking it photoshop will chose the closest colour that is printable. The box below is for web safe colours and by clicking that photoshop will convert the colour so it is web safe.
Save Swatches for Exchange - Saving a palette to use across different pieces of software.
When using a spot colour I always need to see the reference number.
Duotone
Duotone can only be applied to greyscale
Duotone is choosing the inks that are going to be printed, in the process above you can see that I have changed the black spot colour in the image to blue.
Making the Duotone Type from Monotone to Duotone lets me add another colour, this adds more depth to the image. It appears less flat and more stronger.
Adjusting the curve of the inks. Lets me control how dark and bright I want the ink to be on the blacks of the image.
Printing with more inks will cost more, consider what inks I am going to use.
CMYK - 4 Inks
Monotone - 1 Ink
Duotone - 2 Inks
Trio-tone - 3 Inks
CMYK + Duotone = 6 Inks (bad as this will cost a lot!)
Creating a new spot channel
Creating a new channel on the grey image. Choosing a colour lets me draw on top of the image which the colour will then show, but effects the greys in the image. The colour is overlayed as it represents the transparency of the inks.
Adding text will use the channel and show the ink inside the text.
Solidity - As we are working with a channel it appears on screen how the ink will be during the printing process. It appears as transparent. Printing inks themselves are already semi transparent (CMYK). Solidity is to do with how opaque or transparent an ink is.
