Created a figure for a colleague's thesis, want to use that myself as well A colleague of mine who also writes a master thesis in lattice QCD (theoretical/computational physics) asked me to make him a few simple figures with TikZ. They show a fundamental concept and are not particularly hard. The plaquette (see page 3) is just a square with arrows on the lines and then some labels on the edges. The clover term (see page 4) is just four plaquettes. The concepts are fundamental, I could create a plaquette drawing in my sleep, for the clover I need a quick glance at a sketch to get everything right.

It took me like 20 minutes to make the sketches. He has send me images taken from other papers and books to give me the idea. Those figures are used everywhere in books and introductory papers. There they do not seem to refer to anything else but just give the figures. He will submit his thesis with the images next week.

My own master thesis will be due next fall, and I can certainly also use those figures in my thesis. I doubt that somebody will pull up his thesis and my thesis, find the exact same looking images (except the font of the text), look at the dates of publication, and call me out for plagiarizing. However, I'd to handle this situation properly because this situation might arise again with a less trivial figure.

What would I into the caption in my thesis?


“insprired by Author [1]”
“taken from Author [1], typeset in TikZ”
Nothing at all, the other authors did not do that and the figure is not that hard to do anyway


Should I somehow refer to the colleague's thesis although it only has prompted me to create those figures now instead of in six months? I am not sure whether he will say anything about me making those figures, should I ask him to do that such that I can safely use those figures myself?
With all due respect to your TikZ prowess (which indeed is more impressive than my own non-existent TikZ skills), these figures are... not exactly the Mona Lisa. Anyway, they are your work and you should feel free to use them and not say anything at all about the circumstances of their creation. If we had to give credit for every microscopic idea that inspired a turn of phrase or visual idea in the papers we write, they would all be three times as long and virtually unreadable. The situation you are describing is simply too trivial and unimportant to warrant mentioning in my opinion.

As for the future, if in the future you contribute a more substantial intellectual product to a project that then publishes it without an acknowledgement to you, then later want to use the same product in your own publication, then because of the concerns you mention here it may be sensible to accompany the figure or whatever it is with a footnote along the lines of "This figure is the author's original work, and was used with permission in [insert reference to earlier work that used your figure]."