I have had my eye on the Big Shot Pro ever since its premier at CHA. Well, I finally bought one online, and have been experimenting with it. It does emboss 12"x12" designs, which is what I wanted it for. The challenge for embossing 12x12 designs is that there is not a 12x12 cutting platform for embossing available. The instructions for embossing say to use smaller Sizzix platform. That works fine for embossing the Cuttlebug folders, Sizzix texture plates, etc., but to emboss the 12"x12" designs that you cut, you need a larger thick platform.
The Big Shot Pro is now on sale at Joann.com for 40% off, only they don't have any in stock. Great sale! But they do have the Big Shot Pro platforms and extra cutting mats on sale at 40% off that should work fine in lieu of the Sizzix platforms. I ordered some of those, and look forward to experimenting with those. 3 of the standard Big Sho Pro platforms should be the equivalent of the Multi-Purpose platform. And two of the Standard Cutting mats should substitute for the additional Cuttlebug B and C plates needed. Meanwhile, I was able to use a stack of 12 pieces of 12x12 chipboard as the platform, and a couple of pieces of cardstock as shims as necessary. The other item that is not available in 12"x12" size is the silicone rubber mat to place over the cut design. I shopped around a lot, and found Pond Liner at Home Depot. This comes in 15' width, so I purchase 12", so I have enough rubber for 15 mats. It is a bit thinner than I wanted, so I use two pieces. This was a whole lot cheaper than paying $25 from online suppliers for a single 12x12x 1/8" silicone rubber mat.
For testing purposes, I got out some of my Fiskars 12x12 embossing templates designed for hand embossing. These are a full 13" wide, and the Big Shot Pro's opening is not a full 13" wide as advertised - shame on them! I cut a bit off of each of the right and left sides of the embossing templates to make them fit. These templates come two in a set, designed to place paper between them and hand emboss. I use a bit of adhesive to keep them together, and placed those in a "sandwich" on the Big Shot Pro. It took some experimentation to get the best combination of platforms, shims, etc. But it did turn out very nicely. I embossed a very nice 12x12 metallic piece of paper using the Fiskars 12x12 wedding template.
The sandwich consisted of Big Shot Pro platform, 12 sheets of chipboard, 2 standard mylar shims, Standard clear cutting pad, 2 thin Fiskars embossing templates, two pond liner rubber, standard Black mat, 2 cardstock shims.
My next step in experimentation is to cut one of my 12x12 designs from thin chipboard (cereal box thickness) on my Gazelle, and emboss using the Big Shot Pro in a similar manner.
I have attached a partial scan of this project. (I don't have a 12x12 scanner to capture the entire piece, and didn't want to bother stitching it digitally)