Photoshop Workshop

Applying colour skills to Photoshop.

If your designing for print on Photoshop you always set resolution to 300DPI and set the colour mode to CMYK.

Default colour mode for Photoshop is RGB.

Photoshop prefers to work in RGB so all the settings are set up to work with RGB even though you can change settings at CMYK.

However when you change the colour mode to CMYK lots of the filters become unavailable to us.

Open a new document.

Go to colour picker.

 Use the green that makes up RGB, max colour value is 255.

 Our shape is filled with the RGB green.

You then change the image to CMYK colour.

 However you are then left with a duller green, this is the closest green to the RGB colour that CMYK can print.

Open new file, image,

View-Gamut Warning, gives us feedback, whatever colours cannot be printed are changed to greyscale to show us what is out of CMYK colour range.

If you go to adjustments and choose hue and saturation you can change the saturation of the image which gets it back to normal colour and makes it into a colour range that is able to print.

Another way of adjusting the colours to be printable is to go to replace colour and select the colour you want to replace with CMYK, just pick the colour and change the saturation.

Another way to change the colours is to turn proof colours on, it dulls the colours slightly but your still working in RGB but you can use any out of gamut colours.

Before you save it change it to CMYK mode.

To get the swatches palate is to go to window swatches.

To delete colours hold down alt and click on the swatches.

To create new swatch click on the foreground colour picker.

This alert symbol means that the colour is out of the printable range of colours.

If you click on it, it takes you to the nearest printable colour.

Once its in a printable colour range click add to swatch.

Spot Colours.

To get to spot colours click on colour picker and go to colour libraries, all the Pantone books are there.

There is nowhere to type you just type the numbers and they come up.

If you click into the swatches area a paint bucket appears and it will add into your swatches.

However there isn't any reference number for the spot colour.

You loose all the advantages of using spot colour.

Greyscale-never a problem with printing.

Go to image, mode, duotone, you can change the ink the image is going to be printed and you can use spot colours.

 Go to colour picker and go to colour libraries.

You can chose a spot colour and it maps everything that was black ink into your chosen spot colour.

You can change the percentages of your spot colour, its an exact replacement of the original black.

The image is now no longer RGB or CMYK its monotone.

You can change the image to duotone to add another colour.

You move the scale to change the levels of colour in each area 

I changed the levels to the red was in the darker areas of the picture and the blue is in the lighter bits. You can see the gradient scale at the bottom. If you save it you can open it in inDesign and still use the spots colours you used.


Another way to use spot colour.

 Select part of the image, in this case the boat.

Go to Channels, each channel is a greyscale image that defines the amount of that colour in an image.

Choose new spot channel, and go to colour libraries and pick a new spot colour which changes colour of your selected image and is added to your swatches.
The way the colour has been applied it hasn't covered the black pixels its over printing and blends with the black.

If you turn off the grey in your channel it shows you how your spot colour has worked.

If you use the paint tool on the channel then show the grey channel again where you have painted will show up with your spot colour.

If you use the gradient tool you can use to spot colour on your image.

When you save it make sure spot colour is ticked, tif and photoshop file will save spot colours.