In the past, we have subcontracted our direct-to-substrate acrylic printing. This time, we are considering printing the graphics ourselves, applying to Ultraboard (or other substrate?), and then placing this against the second surface of the 1/4" acrylic panels. The acrylic/Ultraboard panels will be 4x8 and wall mounted with stand-offs in the four corners (would rather have 6 stand-offs per panel, but can't per customer). Okay ... here's the question ... even though the Ultraboard will naturally be tacked to the acrylic in the 4 corners with stand-offs, we are thinking the Ultraboard should be completely attached to the acrylic with some kind of invisible bond since the surfaces are large and there could eventually be some separation. We thought about D/S clear VHB tape, but still think it might be seen through the acrylic. These are at a high-end site and need to be immaculate. Any suggestions for mounting the Ultraboard to the acrylic panels? Is there a better method (other than the direct-to-substrate printing)? Thanks for your help!!