What leather sample for my DIY strop

Hope you have some additional tips on my selecting criteria. Just got three small samples of leather in my mailbox. I want to select one of them for my DIY strop. It should replacy my kit strop to a 8cm (3") quality strop with reasonable length.

From top to bottom:
1) light brown grey and thickness of 4mm. More rough compared to samples two and three.
2) dark brown 2mm. Very flexible and smooth
3) black 3mm. Between one and two

Initially I wanted to setup an all black shaving set to match my black scales. The 2nd sample I personally dislike since the look and feel is cheap.

I am in doubt about the first sample; rather thick and grey brown and looks great. Looking at the steampunk strop post this is definately an option.

Question about the roughness, can I scuff it to a more fine structure?

Thx