What is the purpose of paste

[jbcohen]

on a strop?

[SR-CMT]

The paste is abrasive to "touch up" the edge on the razor.

[hoglahoo]

The paste (when a razor is strapped against it) will remove those microscopic bits of metal that get in the way of the stropping motion (and in the way of a sharper blade)

[sicboater]

Some paste is abrasive. Some (dovo white paste) is not and is really just for dressing the strop (increasing friction for better edge true-ing). Chromium Oxide at .5 micron grit seems to be the preferred stuff for touching up a blade. Diamond pastes are used a fair bit as well (again, .5 micron seems to be the go to grit for blade touch up.)

Hope this helps.

-Rob

[Seraphim]

Paste on a strop works much the same way (but much, much finer) as sand on sandpaper-that is to say, it is there to remove metal from your razor's edge.

0.5um Crome Ox is wonderful stuff, so is 1.0 micron diamond paste.

[psdarby]

Paste are just an abrasive used to mildly sharpen a blade. They are also IMHO ( some people probably won't like this ) a crutch for bad honing skills. I'm not trying to condemn pastes, I've used them myself. But I can say that my skills in honing increased dramatically when I stopped using them.