This is the new hot thing. It's paper tape. Original washi tape is from Japan and a type of masking tape. You can buy it from a store or you can make your own. You can find tutorials on it but basically, you take your paper of choice and put it on some double-sided adhesive. Voila. Washi tape. I didn't make it because it's the hot new thing. I'm not into trends. It's actually for layout challenge.
You can use mulberry paper like I did in one of my pieces. You can use tissue paper like I did in the other pieces. Use pre-printed tissue paper or stamp your own. The tissue paper gives a nice, translucent quality to your tape. Some people also use scrapbook paper or wrapping paper. If you want to use your homemade washi tape in your scrapbooks, keep in mind you want to use adhesive and paper that's acid free. Also, if you want the adhesive to last you need to keep that in mind because some tapes adhesives don't. So use those on cards that you don't care about them needing to stick for years.
I chose to stamp my tissue before I ran it through the xyron, but you could also stamp after. Unfortunately, I ran out of adhesive before I could make all my tapes! I did the mulberry paper to see how it would look but I love the look of the stamped tissue paper! I haven't used them yet - I made them and then came to post. LOL