I want to create a file with 1 bit color-depth, i.e. one bit per pixel. Which file formats are suitable for that, and how do I do this in GIMP?
This is for self-created checkerboard for subsequent experiments with image analysis and modification.
PS: I know about How to convert color images to black & white in GIMP? but if I store this as JPG or PNG, there are still gray pixels included.