I want to study the effect of different colored tapes (used to close the vessels) on the proliferation of the micropropagated explants. But in Italy it seems impossible to find these materials.
I do not know about availability of tapes. But I have serious doubts about any measurable effect of this type of treatment. Btw, why do you want to study this? Otherwise, you can study the effect of PAR of different intensity and wavelengths, this can give some significant differences for sure.
Many studies were conducted on the effect of different coloured lights and leds on the vegetative activity of micropropagated plants. So, the light source is investigated. My reasoning is based on a more simple procedural aspect, regarding the possible effect of the plastic layer (of the tape used to close the vessels) as a filter on the quota of light available to explants.