Any of you "older" timers remember the formula for pasting paper targets to cardboard?  Would like you to post them for me if you would.

We use wall paper paste.
Also have used a spray adhesive (but it costs more)

A thin mixture of white flour and water.  Was also used to hang wall paper with years ago.

We used thinned Elmer's white glue. We then applied with a paint roller. Not as cheap as flour and water but faster and not so messy. If I remember right we started with a 2 part glue to one part water but usually it was an "eyeball it" mix.
We used large sheets of heavy cardboard. It took longer to cut the targets to size than the gluing.

Look up a recipe for "wheat paste." Make sure to clean your mixing equipment fast or it's on there for good.

Our club uses wall paper paste also.

My club uses thinned Elmer's.  Sounds to me like any of the above will work.  Like someone on TG said, "There are more ways to kill a cat than just choking it with butter."  I've always like that line.