For my Christmas pictures I want them to be able to fit them inside the card. So I design them in the size of the envelope I will be using, in this case 4.25" x 5.5" . I then bring them in to my photo editing program and put them on a 4" x 6" canvas. That way I can send them to any printer to be printed on a 4"x6" sheet and I just cut off the 1/2" I leave white on the end. To make the background paper the way I wanted it I layered it and then made the top one more transparent so that the small flakes shown through.
Details:Made in MDS