Paint Stick? Painting Crop?

Dear painting experts,
Please tell me that the brush-steadying stick with the sock on the end which is so vital to the painting process that it must be included in Serious & Important Photographic Portraits of such artists as Arnold Friberg and Winston Churchill has a venerable and esoteric name. And then please tell me what that name is. Thank you.
And awesome. Mahl stick. Here’s a lyrical history. Thanks, Jason!
images: Deseret News via NYT; life mag via acontinuouslean]
Related: Norman Rockwell, Triple Self-Portrait