I am sure you can guess!
Corrugated card, painted with acrylic and stamped, twice with contrasting colours. The tissue paper back, background is double stamped lightly with bubble wrap.
I have used 3 Art journey stamps. Film Boy, which I just adore, hope and a ring binder edge. I have used free motion stitching so that the stitches are not regular and also mended a tear in the tissue paper with stitching which I think is rather fun.
This challenge was set by Jo Capper-Sandon for Art Journey. I encourage you to take a look. See what you can come up with for unusual backgrounds.