These were made using printable vintage postcard images I got from Etsy but you can find free printables. The Graphics Fairy has some free ones. I printed out and adhered on some thicker paper and trimmed down and rounded the corners and then collaged and stamped on top. The backs are plainish. They are meant to be tucked into pockets in junk journals for writing on
That’s really cool that you found printable old postcards. I can find them at antique stores ranging from $1-5 each, but I purchase them for the front designs (usually holiday postcards). I like how you put these together, you must have a nice stash of things.