Silly question re: putty for securing smaller pieces for airbrushing etc....

I have a hunk of modeling clay I use sometimes and there's always silly putty as well.  

I take a piece of narrow masking tape turn it upside down curl the ends under then stick it on a large sheet of cardboard then stick the small parts on tape and paint away. Leave the parts on tape until dry ACESES5

I paint a lot of small parts while still on the sprue.  I'll remove all but one attachment point, clearing the rest of the part for paint all around.  When ready to use it, I clip off the remaining attachment and touch up the paint, if necessary.

I use what is often called either "blue tack" or poster putty.  I also use a lot of double sided sticky tape. I keep particle board around for a lot of uses, and cut a "stick" from it to hold parts on, either with the putty or the tape.