The primrose tato is my design. The one in the picture was folded with a 6" (150 mm) square of duo kami paper, and the one in the video was folded with a 8" (200 mm) of the same paper.
If you want to use the model as a greeting card or an invitation, I would recommend to use at least an 8" square. Scrapbook paper (not cardstock) will look nice too.
Here are the instruccions:
Enjoy your foldings!