Andrew Boal offers a shot mask for C4D, allowing for lots of customizations.
Have you ever wished for a good shot mask for Cinema 4D? A new Cinema 4D plugin from Jason James is just the thing. Super Mask can add a custom tag that creates a shot mask with customizable text fields right to the C4D Viewport.
Super Mask allows for the customization of color, fonts, font size, and a watermark or branding image. Just like most other camera masks, Super Mask only renders in Viewport renderer.