Extended Data Fig. 6: Testing melanin BC color fastness with water spotting test.

The top illustration demonstrates the water spotting process. Photographs of dried melanated BC from both K. rhaeticus strains, with and without glycerol treatment are shown at three time points: before water spotting, immediately after water spotting and 16 hours after water spotting. Images are representative of 3 water spotting tests for each pellicle and treatment.