easy-to-build sample for spectral unmixing
- get a small piece of thin paper/ tape and put it on a slide
- draw a line with a yellow highlighter across the paper and a short range across the adjacent glass surface
- draw another such line with a red highlighter, it should cross the yellow line on the paper
- mount such that the paper and the parts of the lines on glass are all covered by a coverglass; as most mounting media will dissolve the dyes try mounting without mounting medium, only fixing the coverslip on the edges.
- you now have a sample with 3 spectral components (yellow highlighter, red highlighter, paper) with overlapping spectra. Using not too narrow bandpass filters you will be able to observe bleedthrough. On the slide, each component can be measured in its "clean" form to take a reference but is also available mixed with the other components.