paper under glass mosaics

Hi All!...well I am stumped.. I have been searching for info the past few days and that is how I found this website. I have been doing some mosaic projects..some I have sold and some not as of yet. I am in the middle of doing a mosaic mirror and I know what I want to do on it ..I have the vision for it but not the complete know-how. I am doing a large "God Bless America" mirror and have wanted to put some artwork that I made on my computer under some clear glass. I printed it out on card stock, glued the glass over the artwork and then glued them as one piece to the board. The problem that I am having is I cannot get the glass to smoothly adhere to the paper without leaving it looking bubbly under the glass or smearing the ink on the paper when I try to apply the glue. I have tried Mod Podge and spray adhesive but I still do not like the way it looks through the cut piece of clear glass. It also has to be waterproof so I can grout it in. I found some pieces that others have done that seemed to come out beautifully but how do you ask someone their trade secrets. :( Does anyone have any pointers and is there a specific name for this kind of paper and glass technique in mosaics. Thanks for your help and look forward to hearing from you.