Procreate is a great painting app for the iPad, and its swatches file format is one of the formats supported by WheelMasks. In this post I'll explain how WheelMasks and Procreate can work together showing how I used a wheel mask for this portrait.
First, I created my gamut mask, choosing an atmospheric triad with red, green and cyan as my subjective primary colors.
Then, you can send your palette to Procreate. Since Procreate's palettes can have at most 30 colors if your selection is larger than that it will split it in groups of 30 swatches or less before sending them to Procreate.
If you're curious, here are the two palettes in Procreate's format:
I personally prefer to work directly with the color wheel, so I just pasted it on Procreate. I also prefer to have more colors to choose from so before I did that I increased the number of hues and levels to the max.
In this screenshot you can see how I've placed the wheel mask as the top layer and I how colored the background with the neutral color for this color scheme (that's the color in the center of the mask). Here the painting is already finished and the background layer is mostly covered, but starting from a base color helps me paint the rest of the painting.
I keep moving the mask layer around depending on what I'm painting but all the time it's the top layer, by the end of the painting as I tend to pick colors already in the painting I usually hide it.
I only pick colors inside the mask, or from the swatches table, but I tweak them afterwards because you don't need to use the exact color you pick. A mask should be seen as a guide, not as a strict rule. However, I try not to change it to a more saturated color, that could produce an out of gamut color.
For instance, I picked the following orange, but when I tweaked it tried never to cross the red line to the right so as not to get a more saturated hue which would be outside my mask.
In the following posts I'll share more examples with other apps and a more detailed tutorial of how to use gamut masking.