Photoshop
When setting up a document for print on Photoshop, the resolution is to be set to 300.
- there's no point going above that when sending a document to print as it wouldn't make any difference to a 300 resolution version as it's the cut off.
- you can use a larger resolution when working with things like photos in order to be able to enlarge the photo to fit a bigger scale.
Set the colour mode to CMYK, as this is for print.
- RGB is for screen.
RGB is the default colour mode for Photoshop.
To change the colour mode of an image once it is open if it is set to RGB, go to Image > Mode > CMYK colour.
The risk of working with RGB is that it has a wider spectrum than CMYK does, so if you work with a colour only available with RGB you then get an 'out of gamut' colour in CMYK.
When using the colour picker in Photoshop, and you use the RGB options to enter colour values, 255 is the highest it will go, and 0 is the lowest.
Once this is done, if I then change the mode of the document to CMYK there is then a colour shift to bring it back within the CMYK spectrum.
To work just in CMYK creates larger files when saving them in Photoshop.
To check whether an image you have been working on has colours which has shifted out of the CMYK spectrum, you can go to View > Gamut Warning.
Makes the image go from this:
To this:
You can alter it so that the colours shift back into the CMYK spectrum by using the Hue/Saturation option.
Also, you can use the 'Replace Colour' option.
Another way of spotting where colours are outside the CMYK spectrum is by using View > Proof Colours
This is a good way of working because it shows you the image in both RGB and CMYK. Basically you are still working in RGB to be able to use Photoshops full potential, but shows you what the image will look like in the CMYK mode. Then before you save the image for what ever reason, you must remember to convert the colour mode to CMYK.
To do what we were looking at last week with the colour swatches and using your own colours, you can do the same using the Swatches on the right side.
To delete the colours already in the pallet, hold the Alt key and click on each colour individually.
To create a new colour, you click on the Foreground colour on the left side. then click/find the colour you want or need to use. You can do it by clicking in the colour spectrum that appears on the left, or use the CMYK %'s on the right.
An easy way to ensure that the colour choosing is within the CMYK spectrum, is by the little box that appears next to the colour with the little warning side. you can click it to find a nearby colour.
When you click it it doesn't always find the nearest colour match though.
When you have the right colour you then click the Add to Swatches option on the right side.
This adds the colour to the swatches pallet, as well as sets the colour as the Foreground colour.
To select a specific colour that may be used as a spot colour, again you click the Foreground colour and select Colour Libraries.
In order to know what 'book' to choose the colour from, talk to the printer to discuss which would be best for the stock your intending to use, then select from the drop down menu.
To select a specific colour, even though there isn't anywhere to type the number if you just type it then it automatically finds the colour for you.
Then when done, click back on picker and click add to swatches the same as previous.
The problem with doing this though is we won't have the reference number for the colour, so need to save it as the right one.
There are two ways that you can use spot colours in Photoshop. The first way is to have a greyscale image.
When you have a greyscale image, one of the things you may want to do is to change the brightness and contrast.
A way to change it so that it isn't printed with black ink, but with a spot colour you can go to Image > Mode > Duotone
This changes the black to the spot colour.
Using the box to the left of the colour, this allows you to change the % of which the colour matches the % of what the black was.
You can add a second spot colour by changing the option in the drop down menu from monotone to duotone, then select a second colour.
You can then determine how much % each of the colours grasp the image by altering the curve options.
When you save this then as a Photoshop file and place it over into InDesign, it will then add the pantone colours to the swatches pallet in there allowing you to then use these colours within other elements of the page to ensure that the same spot colours are used consistently.
The next way to add a spot colour to a greyscale image, you can do it by using selection tools. Then use the Channels option on the right. This has 4 different layers for each of the colours, such as one for Cyan, one for Magenta, etc. They are all in greyscale when you click them. Every image has channels and are used to select colour. So first I make a selection within the image.
Click on the Channels pallet.
Go to the menu option and go to New Spot Channel...
Then the same as before you go and select the specific spot colour you cant to use.
This then applies to the selected area.
Then when you click ok, this then adds another Channel to the pallet for the specific spot colour selected.
One of the good things about using a Spot Colour Channel is that you can go back and edit it at a later time if you wish. Also, you can paint on to the spot colour layer in the Channel section to add more of the colour, or refine what I have selected, or can add a gradient to the image by adding it to it.
You can use the application of a spot colour to be able to use it then as a spot colour within a printing process. You do it exactly the same, but specify to the printed what it is you actually want them to do.
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