It is so difficult to get the post to stay in the tack he uses to stick things to the glass, and then to have the blade or bullet stay stationary as well, while it lay on the glass on the table.
I don’t know what kind of tack your photographer uses but I like
QuakeHold Putty (Q Safety Product #4080) made for keeping things
stationary during earthquakes. You can check it out at
http://www.qsafety.com/ . I also use it in my display to stabilize
cases that are stacked, as well as to hold pieces of jewelry on
sloping surfaces.
Beth