Best glue to use for pictures / hardboard

[kfitzsimons]

I mount photographs on 3/8" hardboard, then glue 2 vertical 1.5" wide strips of poplar to the back, screw in two hook eyes, and join the eyes with picture frame wire.  I paint the edges of the hardboard black.  The look really nice hanging on the wall.  To attach the poplar strips, I've used Liquid Nails, Titebond III, and Gorilla Glue.  GG holds best, but oozes out of the edges (can't be seen from the front while on the wall, but it looks tacky). Both the LN and Tb III have failed and the pictures have fallen off the walls.  I tried using a pin nailer through the hardboard into the poplar strips, but it dimples the front and it shows on the photo. The hardboard is very smooth which might be part of the problem. Any other ideas for a glue to use?  I make these as large as 30" x 40".