Does diamond sharpen more than other pastes?

I've read everything I can find about the subject of pastes. There's one thing I'm not sure of still. Most pastes, it seems, help refresh an edge by smoothing out the very edge of the razor. They don't "cut" into the steel and therefore don't increase the bevel length as honing does. Eventually pastes don't work and the razor much touch a stone. My question is, are diamond pastes and sprays an exception to this? Because diamond is hard and potentially does more cutting, does it in fact lengthen the bevel like a stone? OR, is it less the paste used and more the motion used in honing that effects this (ie. because you hone with the edge leading, this is what truly cuts and lengthens the bevel)?

Pastes definitely remove metal. In fact, there are buffing compounds that use chrome ox as the abrasive. After a lot of use, you'll see black on your pasted strop (from the removed metal). Diamond pastes/sprays seem to be on the more aggressive side, so you may notice it faster.

I think the reason that you need to go back to a hone sooner or later (or at least what I read or was told) is because the strop doesn't remain flat, so there is some rounding that goes on at the edge.

There may be more to it than that... I'm not too into stropping, let alone pastes.

As far as the effect pastes are pastes. It's the method more than the material. Diamond is more aggressive and cuts more, yes but the end result is the same. Diamond especially .25 can leave a harsh edge on a razor.

Does diamond sharpen more than other paste? Yes and No.

Anything after setting a bevel, (getting the two bevel plains to meet and creating a sharp edge) at 1K is polishing the edge. By polishing the edge we are reducing the height of the land to the groove of the scratches on the bevel and edge left by the grit on the 1K stone. The more you can reduce the height of the land, the more comfortable the shave, the more you will reduce the microscopic serrations on the edge. The serrations cut into the skin, the more sensitive your skin the more you need to polish the edge to get a comfortable shave.

Can one refresh an edge with diamond? Possibly, if you have mastered the stropping skill. The better solution is a finish hone, then paste for comfort. Diamond is more aggressive that most paste and can be used to refresh a failing, yet serviceable non damaged edge. But if it need re honing due to damage, it needs re honing. Different types and grits of diamond pastes & sprays will produce different result on different kinds of steel. So experimentation is in order.

Once honed and shave ready, paste can keep an edge shaving… indefinitely, before the edge begins to fail. Honing is completely different than stropping on a pasted strop and it does not matter the mechanics of the direction. We strop away from the edge because stropping edge forward will cut your strop medium. Honing on a high grit stones with slurry and or various paste yield mixed results, mostly depending on technique and skil. They are all polishing the edge with progressively higher grits.

Stropping on a pasted strop is polishing the already sharp edge, as is honing on high grit stone with or without paste or slurry. Honing is re grinding a bevel and edge. Hones are much more course than paste, finish hones end at 15-30K and possibly you can squeak higher grits with slurries. Most paste start at .50 microns = 30k grit and go up to 160K.

Unfortunately for the novice, a pasted strop can cause more damage than it can resolve. It is after all an abrasive strop, and technique matters... Bottom line is, pasting and honing are different techniques for different problems. The line does blur a little but not much. Often a touch up with a finish hone to re build the edge, then re-polish on paste, is the quickest and best alternative. Much of this hobby is learning the ability to diagnose problems, often there is more than one way to resolve the issue. It usually comes down to skill and availability of tools at hand.

Read and ask as many questions as you can, then experiment as much as you dare. It is… how we all learned.