Figure Headings in Laboratory Reports
Provide all the data that are necessary to reproduce the experiment:


TLC material (silica gel or aluminium oxide)
composition of the mobile phase
special tricks, such as running the TLC in methanol first for 5 mm to squeeze the initial spot to a very narrow band
detection of the separated bands/spots:

$\mathrm{R_f}$ values
do the spots have a colour
do the show fluorescence
which reagents did you use for staining




UPDATE

If you report on a series of measurements, it's usually good practise describe the conditions that didn't change (type of TLC plate, staining solutions, etc.) in the general section of the experimental part of the report/article/thesis.