Masks can often be a source of confusion and mystery for people when you first set out on your Photoshop journey. However, once you get the hang of them they soon become a “can’t live without it” tool. In this tutorial we will go through some of the basics and how they can be used.
What is a Mask?
Putting it simply, a mask either shows or reveals parts of a layer or a layer effect. Where the mask is White, the layer or effect it is attached too will show through. When the mask is Black, the layer or effect it’s attached to will be invisible. A big plus with this is that we can make an adjustment to part of an image in a non destructive way so the original layer remains untouched.
Lets go through a few steps to demonstrate this. If you want to download the image I’m working on to follow step by step you can find it here by right clicking and “Save image as”. And as always clicking on an image in the tutorial will make it BIG 🙂
Lets Get stuck In
Once you’ve opened the image (Or your own) than the first step is to duplicate the layer, this can be done by selecting the background layer and pressing “Ctrl J” (or Cmnd J on Mac) or by going to the menu bar and clicking LAYER>>DUPLICATE LAYER . This is generally good practice whenever you work on an image. If things go wrong at any point you can always come back to the original.
What we are going to do is change the colour of one of the peppers by using a mask. To do this we will first add a Hue/Saturation adjustment layer. This is achieved by either clicking on the icon that is a circle coloured half black and half white at the bottom of the layers tab, then selecting HUE/SATURATION from the pop up menu. Or by clicking on the HUE/SATURATION button in the Adjustments tab. The image below shows the location of the button and the Adjustments Tab.
When you do this you should see a window pop open in the adjustments tab (The location will vary depending on what version of PS you are running and how you have your workspace set up) The window will have three sliders, Labelled “Hue” “Saturation” and “Lightness” as seen in the image below. You will also see that in the Layers Tab, an adjustment layer has been created, and it already has a mask attached.
We are going to use the Adjustment layer to change the colour of the peppers. As Hue and saturation only affect colour, the background will remain white. So grab the top slider and move it left or right to change the colour. I went for a nice shade of purple found at -62 on the hue slider.
The first thing you will notice is that all the peppers are now a pretty shade of purple but we only want one purple pepper. The reason the adjustment is effecting the whole image is because the mask on that layer is white. Remember that where the mask is white it lets the effects of the layer show through. The next step is to turn the layer mask black to hide the effect from the whole image. Single click on the mask so it is selected, then Invert it. To do this either press “Ctrl+i” (Cmnd+i) or make sure the mask is selected then on the menu bar click IMAGE>>ADJUSTMENTS>>INVERT .
You will now notice that the peppers have gone back to being red, and that the layer mask icon on the adjustment layer has turned black.
Paint the effect back in.
Alternatively press “B” on the keyboard and select a round brush with a hardness of around 60%. Select white as the foreground colour for the brush by pressing “D” on the keyboard which is the shortcut for selecting the default colours of white for foreground and Black for background. Now make sure you have the mask selected and just paint over the pepper that you want to make purple.
The beauty of masks is that if you make a mistake you just change your brush colour to Black (If you press “X” on the keyboard this is the shortcut to swap background/foreground colours) and paint the mask black again to hide the effect.
If you want to change the colour of another pepper then just repeat the steps, The mask controls the effect it is applied to. Add another adjustment layer by selecting Layer 1 then clicking on the Adjustment layer button (Circle half black and half white at the bottom of the layers tab) and selecting Hue/Saturation. You can change the colour again with the slider (I went for a sickly green at +67 on the hue slider) Again the adjustment effects the whole image until we invert the layer mask by selecting it and pressing “ctrl (cmnd) + i “ Now just paint white on the mask where you want the pepper to be green.
Now at any point you can click back on an adjustment layer and change the settings and the changes will only be visible where the mask is white.
Masks are capable of doing much MUCH more than this, but hopefully this tutorial will have helped you grasp some of the basics and get your mind round how they work. In the future we will look at some more complex ways of manipulating masks. Cheers for reading guys, and please feel free to leave any questions in the comments section 🙂