Film holders with variable height - any good?

[papo]

I have seen them on this website and wondered if there is someone who actually has them an can confirm that they could improve the image quality.

Currently i have an Epson V550 Scanner and would like some improvement in my scans. Thanks

 

[Karlovak]

Try credit cards stacked on both ends. Two, three maybe four?

 

[papo]

good idea but i would also like a film holder with glass in order to keep the film flat.