Best Build Your Own Palette System

What’s the Best Build Your Own Palette System that you’ve tried?

Share your pick!  And don’t forget to share why :)

MAC and Inglot both have a good system, as it makes sense to buy pans or larger palettes. Their ranges are both huge, so there are plenty of shades to choose from. I love Make Up For Ever’s Artist Shadow range, but good luck getting a palette larger than a trio.