
(examples of different card frames, as well as the reverse)

(comparison between proxy and original)
Some thoughts:
1) These are just quick mockups by me using the existing low-res MECCG card images and replacing the black borders with gold ones. I didn't darken or lighten them at all, and I'm pretty pleased with the results using the original brightness unchanged. Any graininess, pixelation, or color variation comes from the source images, not the printing process.
2) That being said, no one with any exposure at all to actual trading cards would be fooled by these. They're thicker, ever so slightly taller and wider (it's a struggle to inner sleeve them, and the card bends slightly to fit), and there's a weight and glossiness to them that's quite unlike original cards. If you're thinking about sleeving them, I'd say a single-sleeved proxy is roughly equivalent to a double-sleeved original in terms of fit and feel.
3) The gold borders and back are every bit as good as I had hoped. If someone does pursue more widespread proxy printing in the future, I think this would be a great way to go. The four card frames I chose (hero character, hero resource, minion resource, hazard) all looked excellent when bordered in gold.
4) Though the forum resizes them to fit your screen, the images in this post are quite large, so if you'd like a closer look, just right-click them and choose "Open image in new tab" (or your browser's equivalent).