Options for gluing thick paper to acrylic sheet I would like to mount a photo to a clear acrylic sheet. The way I am planning to do that is by first gluing the photo to a thick paper sheet, and then gluing the thick paper sheet (e.g. 250 gsm) to the back of the acrylic sheet.

What are my options to glue the thick paper sheet to the acrylic sheet such that the whole thing has a professional look (not a kids project look :) ).
To prevent warping, you can dry mount, or use high-quality double sided adhesive sheets. 
Cut the sheets to size beforehand (leaving, if desired, a small border of a couple of millimeters around the sheet to prevent it from sticking out from underneath), place the sheet onto the photo carefully, applying pressure from the center outwards.