Dear Mr. Meglio,

I have recovered several old markers of various diameters (this is a penance for those who work with gait analysis).

For spheres of 10mm maybe "3M Scotchlite Reflective Material 8850" may be more appropriate, because the thickness is smaller and the base is made of rubber.
https://www.motion-labs.com/prod_access_scotchlite.html

I cut the tape in small rectangles with a width of ~ 3mm and variable length to reduce the overlap. Some overlap will always occur in this process, but this did not present a significant image distortion - you can inspect the reflection and shape of marker with a photo made with the flash cam enabled.

I apologize for the translation mistakes.
Best Regards.