England has several sites that cater to paper embroidery. There are many ready made patterns and kits and you will also find free patterns as well. Form-A-Lines was one of the first craft companies to offer kits. Stitching Cards also has much to offer.
Our swap this time was any style of Valentine card as long as it had embroidery on it. I used a section of a free pattern for the center and designed my own border. I attached the center to the border with ribbon and then glued it to a card form and finished stitching and adding beads.
There are oodles of sites and information on the web. Here are a few sites to get you started...