I exactly don’t remember when I made it; probably more than one year ago. I made it as an exercise without paying attention to technical matters anymore. It is the only work I used a background.
One of my habits is that I often delete my files after a while. I delete those files that I think are not notable or interesting, whether my designs or writings. I think it is not a good habit.
Most likely, I deleted the file of this plane as well because I couldn’t find it on my system.