I don't shave with a straight razor, but I do sharpen carving tools for woodworking.
I strop with a fine honing compound on the strop, and the purpose of that for my application is to get a more highly polished edge than I get off of stones. The[0] explanation among woodworkers being that a more polished edge has fewer micro serrations along the edge that create weak points on the edge for dulling to start. If the edge has fine points from coarser (relatively) stones, they can break off, leaving a definitely non-sharp region behind. Or something like that.
Other tools that are frequently stropped include drawknives. Chisels and plane irons are less commonly stropped because the softer strop inevitably reduces the flatness of the blade at the cutting edge[1].
[0] Ok, one explanation. Some woodworkers will argue bitterly about anything related to sharpening.
[1] The importance of which is another topic that woodworkers will argue endlessly.
I strop with a fine honing compound on the strop, and the purpose of that for my application is to get a more highly polished edge than I get off of stones. The[0] explanation among woodworkers being that a more polished edge has fewer micro serrations along the edge that create weak points on the edge for dulling to start. If the edge has fine points from coarser (relatively) stones, they can break off, leaving a definitely non-sharp region behind. Or something like that.
Other tools that are frequently stropped include drawknives. Chisels and plane irons are less commonly stropped because the softer strop inevitably reduces the flatness of the blade at the cutting edge[1].
[0] Ok, one explanation. Some woodworkers will argue bitterly about anything related to sharpening.
[1] The importance of which is another topic that woodworkers will argue endlessly.