I use the same as Vectis - Clearview is the make that I have and see most frequently. Most pet shops sell it now in a variety of depths and images. As it is on a roll, you'll be able to get a long strip for the Detolf. It's good quality image and makes such a difference. It's double sided, so depending on the two images you can change it for different hamsters.
You can see the variety of images at Seapets:-
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