I know some probably know this already, but to you vaseline users, it is
possible to do those masks without the greasy stuff. In our middle
school we have used plastic wrap (Saran wrap) to cover the face( leave
nostrils open). Then a piece of cardboard with an oval cut out for the
face is placed on the student's face. This helps guide the student in
the placement of the plaster strips. We've been doing it with the
plastic wrap for years with great results and no gooey vaseline mess!
Try it and let me know what you think.