Hmm, maybe it's more effective for something else?
I don't know, maybe I'm not using this brush correctly, but it didn't seem to pick up any of the RMS Living Luminizer when I tried it. The luminizer is solid at room temperature, with the texture of a lip gloss. So I've been applying the luminizer with my fingers, which is obviously not going to give me the most precise application, but I should give this brush another go. The effect of the luminizer is supposed to be subtle so that your face looks fresh and dewy, after all.
It is a nice adjustable brush that extends and retracts when you twist the handle, presumably to allow more precision with the bristles either held close or more splayed out.