Step 2 Now change the black linework to blue. With the linework layer selected, click on the Channels tab in the Layers palette. At the bottom of the window is a button called ‘Load Channel as Selection’. Click this, then return to the Layers tab and create a new layer. Now you can draw with any colours you want. Next, go to Select > Save Selection. Then invert the mask (Cmd/Ctrl + Shift + I).
Step 3 Start separating out the shapes – in this case, the waves, the objects and the figure – with masks. You’ll need to use the same method as in step 2 to create a mask (fill the shape with black, load the Channel as a selection and then create a mask). Again, make sure you save each mask (Select > Save Selection) as you’ll need them later on.
Step 4 Now we need to fill the shapes of the objects. If you get bored of just using black to fill the space, you can use colours instead. Once you’ve finished the filling in, go to Image > Adjustments > Hue/Saturation, then change the saturation and lightness to -100. This will make all the colours you’ve used instead black.
Step 5 Once you’ve created all the masks, start colouring your shapes using the mask layer that you created for the detailed background (in this case the waves of hair) in step 3. To load the saved selection, go to Select > Load Selection.