Today’s item is barely there, gossamer wings and a steel staple.
It is a pre-formed gift ribbon.
The ribbon is barely stopping any X-Rays, so hardly shows up at all (x-Ray images are basically shadow images, if the object doesn’t make much of a shadow, you don’t see it). The staple at the bottom, holding the ribbons in place, is made of steel and stops the X-Rays nicely. The extra whiteness around the staple is due to rust – the staple rusted at some point and the rust has migrated into the ribbons. Rust contains iron, and iron is good at stopping X-Rays – hence it shows up in the image.