OUGD 504 - Studio Brief 1

In this session, we are looking into Photoshop and how we can use it when editing images and working with colour. We need to start thinking about inks and the ways in which they are applied:

When working in Photoshop, you can instantly tell the colour mode of every image in Photoshop as it is displayed within the title bar or tab. You can change the colour mode by going to image, then mode and by choosing one of the various colour settings. Obviously, CMYK is for print and RGB is for web. One of the differences is the actual colours that are available within each mode. There are colours that you can produce in the RGB colour mode that cannot be reproduced within the CMYK colour range. The 'gamut' is the range of colours available.  If you go to 'View' and then 'Gamut Warning', you can see all of the colours that cannot be printed. These colours can be manually altered by using tools like 'Hue/Saturation', but more the use of an adjustment layer is much more efficient. 

In order to ensure that all of the colours are in gamut, I have simply slightly altered the Hue/Saturation of the image. By reducing the saturation slightly, you are able to correct almost all problems that the image may have. We then looked at 'Proof Colours' and how these are used.

When 'Proof Colours' is checked, at first it may seem as though nothing has really changed. However, when you now look at the title bar of this document, you can see that it now says RGB/CMYK; although we are working in RGB we can still see how it will look if we were to print it.

‘Work in RGB mode until you finish your 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 adjustment layers to make corrections. These adjustments should be very minor. Flatten the file is necessary, then send the CMYK file to the professional printer.’

We are now going to delete all of the swatches that we no longer need. Unlike Illustrator there is no trash can for the swatches, but instead you have to hold alt and click on the swatches that you want to delete.

To add a new swatch, select your chosen colour and then click on any part of the swatch panel that is blank. You can't save your swatches if it is completely empty; you always need to have one swatch left.

When selecting a new colour, you can sometimes see these two small icons next to the colour panel. The icon on the top means that this colour is out of gamut, whereas the icon on the bottom refers to this colour not being a web safe colour. You can also use the Pantone Colour Guide, as well as spot colours, to aid in the selection of colours. Spot colours can help you print images using less inks. You can type in the colours number in order to quickly and easily find it in the pantone range. It doesn’t matter if the spot colour is out of gamut when working at uni, as you wouldn’t be using CMYK to print it.

The only way a spot colour can be printed is if it has its unique reference number. If you apply a spot colour to a CMYK image, it will have to be printed with Cyan, Magenta, Yellow and Black. In Illustrator, CMYK and spot colours can both be used. However, Photoshop has no spot colour mode.

A ‘Grayscale’ image only uses one coloured ink, which is black. The duo tone option isn’t available when working on an RGB or CMYK image, it has to be a Grayscale image. If you go to the Image menu, then in the Mode menu you can see Duotone; this also allows you to use spot colours when working with images.

This allows you to quickly and easily apply a single colour overlay to any grayscale image, like seen above.

You can then edit the curves of the image, which changes how the new ink is mapped to your old ink. It remains editable so if you want to change your spot colour, you can. However, if you want to use two inks, you can choose the ‘Duotone’ option.

By reversing the curves of the second colour, the yellow, it means that this ink is applied more to the areas of the image that were white and less so to the areas that were black. In order for our spot colours to work effectively, and remain editable, we need to ensure that we save our files as Photoshop files. ‘Channels’ is a way in which Photoshop stores information about the different colours; these are used for both CMYK and RGB images.

If you make a selection and then add a new spot colour, it automatically fills the area with your chosen colour. It is like working with blend modes. Solidity refers to the opacity and transparency of the ink. By applying a spot varnish professionally, you would use a spot channel and apply colour to the area that you want the spot varnish to be applied to.

When you save the file, a Photoshop file or a Tiff will allow the layers to remain editable.