Dawn, I have had great luck with regular Plexiglas.  I had a sheet cut (at
Home Depot) 24" high and a little wider than my doorway.....maybe as much
as 3 inches.  I don't remember how much wider and I'm at work so I can't
check.  24 inches is about as high as I can easily step over.  It bends
easily and fits against the door stop from inside the room (it bows into
the room).  Pressure holds it in place and when they push against it, they
are pushing it into the door stop......and it's cheap!
 
I found that soon my kids were able to jump until they caught their claws
on the top edge and scrabble on over so I posted to the FML and got a great
suggestion.  Once again at Home Depot, I purchased a length of bendable
plastic tubing (not pipe), 1" diameter and a little shorter than the top
edge of the Plexiglas for clearance.  I slit the tubing down the entire
length and wrestled it on to the top edge of the Plexiglas (it was a job).
The tubing bends with the Plexiglas and, when in place, the kids don't have
anything they can hook their claws over.....the diameter is too big and the
tubing is too hard and slick.
 
I'm sure this cost less than $20.00 and is virtually the same thing as the
Weezl Watchr.  I think polycarbonate is supposed to be more resilient, but
the Plexiglas has been up for some months and shows no sign of splitting.
Also, When Fidget and Fannie are out, I just use it to block an adjacent
doorway into a forbidden room.....dual purpose!
 
Good luck!
 
Paula....andFannie&Fidget
[Posted in FML issue 3140]