I have been looking at Queenie's cards for some time thinking, "Gee that's a great idea." So when I was looking for something else I came across some trial designs I had stitched and immediately thought, "a card". Small problem. I didn't have a card with the right sized window so I had to cut a larger window in a card I already had, not very well. ( I think that I will glue a border around the edge to hide the cut and frame the embroidery and also buy some cards with larger windows.) I stitched this using a silk thread and stem stitch, all stitched in one direction.
I want to stitch some Xmas cards this year and that smaller window will keep the designs smaller, not like this one. I have also been ruminating about how to make embroidery cards for little kids. I started my grand daughters on laced cards and that was great but there needed to be another step between that and stitching on aida cloth. Then I came across a scrap booking site by Jennifer Mc Guire Ink where she has a whole section on stitching on cards.
In this post she has a link to a very detailed video she has posted to You Tube, 38 minutes of detail. A lot to think about here.