I don't know, but someone will. You are SO brave!

You don't need to actually embroider on the card stock...One way I like to do it is to hoop tear away stabilizer, then float a rectangle of Peltex by Pellon, then on top of that your fabric... You will treat this like an applique...for example, rectangle run stitch on the layered materials... trim only the fabric to the stitching, decorative or satin stitch to cover the trimmed rectangle...embroider your design in the center on fabric/peltex/stabilizer. Once finished, remove from hoop, trim the Peltex/Stabilizer about 3/8" or more around the embroidered fabric...You can add an additional color of card stock under the Peltex if you choose to, and then with glue or double sided tape, adhere to front of your card...The back of the embroidery is covered by the original card, and the Peltex gives a great base for the embroidery....I don't have a photo of one that I have done handy, but here is a photo of one that looks like it was done in a similar way manner...

I'm so glad you asked this question. And a big thanks to Dragonflyer for the instructions and the beautiful pictures of the cards she has done. I hope you now make your own beautiful cards and b sure to post your pictures in Projects.

Here is an Anita Goodesign video for making a card...they are using standard card stock and felt for the "fabric applique" part... As I relayed below, I use the Peltex between the fabric/felt and the card stock...and I use glue or double sided tape to tape the Peltex/Fabric card onto the card stock... That way, the embroidery is covered up and no need to add a piece of colored paper inside to cover your embroidery... I have also done this technique on purchased cards with a message inside...I just cover the outside print of the card with my Peltex/Fabric appliqued piece...I sometimes even use light batting under the fabric and over the Peltex if I want a quilted or puffy look to the appliqued fabric on the Peltex...
https://www.youtube.com/watch?v=NiJzE01i8Hk

Here is a link for the Embroidery Library tutorial for embroidering on card stock....

https://www.emblibrary.com/EL/ELProjects/Projects.aspx?productid=PR1165

Hi, its a while since I embroidered on card and the advice I was given was see what works for you. Have fun and show us your results