Design Production: Print Workshop 2

In todays session, we looked at how to work with colours in Adobe Photoshop.

Once Photoshop is open, first check the colour mode to see if the file is set up how you need, CMYK, RGB etc.

Photoshop files usually open in RGB, which is the standard file for web based design and the computer screen.

RGB colour is an additive process whereas CMYK is subtractive.

Design for print has to be set up to work with CMYK, which is a bit of a dip from the bright colours available with RGB and spot colours. CMYK mixes the ink on the page which can only create darker with more layers, whereas RGB being light based mixes into white, leaving some colours being unable to transfer to print via CMYK due to the gamut of the inks.

In Photoshop, we still work in RGB when designing for print, but can use a couple of tools in Photoshop to check whether the image will be printable by using either the 'Gamut Warning' or the 'Proof Colours' tool.

If prompted, the 'Gamut Warning' shows the areas of the image unable to translate to print as a grey mass, as pictured below.

You can render this problem though by opening up 'Hue/Saturation' and lowering the saturation, in effect dulling the image and reducing how vibrant the original was.

 

 The other way to check if the colours in the image are all suitable for print is by the 'Proof Colours' tool, just above the 'Gamut Warning' option (which is probably a better tool).

This indicates that the 'Proof Colours' tool is on, showing you're working in RGB colours but it's showing you the image you'd see, or a closer representation to the print, in CMYK.

Adobe Illustrator swatches can be displayed in CMYK percentages if the user wants, however, this isn't available in Photoshop. Bit of a strange thing to leave out, but you can have a palette which can be opened across Ai, Ps and Id when the swatch library is saved as an ASE.

To clear your swatch palette in Photoshop, you can't just delete all the colours at once because there is not an option to do so, you have to delete them all individually. Once deleted, add one colour to swatch palette and save the swatch as a blank swatch and a good reference for a document that you'd need to remove the swatches from.

To open the blank swatch palette, from the same menu, select 'Replace Swatches...'

Any colours that can't be translated to print, show up in your palette tool with a little exclamation, similar to the default one on Illustrator.

The easiest way to apply a colour to a swatch is to have it set as a foreground colour and then move your mouse over the swatch menu and click and then add it

Working with Spot Colour

Spot colours can be good to set out gloss and other processes along with being exact with your colour. Spot colours come in the form of coded 'Pantone' swatches.

Creating a duotone image can be a good way of utilising colour and limiting how many single colours to go into the piece, reducing cost from expensive and not so sharp CMYK printing, to spot on spot colours, with the exact colour matched before printing. Before you create a duotone you need to convert the image to grayscale and then correct your levels so you have a well contrasted and exposed image, once done you can convert to duotone.

From the Image menu in 'Adjustments' there is an option for 'Curves' which can be used to control how the colours are distributed.

From the duotone option in Photoshop, you can mix upto four colours creating a 'Quadtone' image, to some interesting effects.

Spot colours can provide monetary rewards because they're cheaper to print requiring less inks, when working with spot colours the image will only work in greyscale. 'Image > Mode > Grayscale'.

Using Spot Colours with Channels can be beneficial to setting up your artwork, making sure that the colours you want are where they are.

When using Channels, the Channel stores the information on the Spot Colour and how it will be applied to the image.

Once the Spot Channel is selected then you can use the brush tool to paint over parts of your image that you want to have the Spot Colour applied too, this can also be done with selection tools like the magic wand, lasso etc. Instead of a solid block colour fill that removes details, the channel option masks the image with opaque colouring.

 

Spot Colour can be used to notify the printer where you want a varnish or a glue, use a colour that doesn't already exist in the artwork and notify the printer of this addition.

If you open up the artwork that includes Spot Colours into InDesign or Illustrator then the colour reappears and the swatch is there, enabling a solid colour to run through all products.

Save any files with Spot Colours as a tiff file format, along with the Spot Colour box, ticked.