Well, that was lovely!
Thanks again to Chris
@Boycie83 for sending me a pack of these Shark blades. My principal interest in these initially was for the ROCNEL SE-P as I saw them available as half blades and I think my query has been answered: yes, I'll bag a little box of 100 for single edge use. If I fire up the ROCNEL SE-P in the meantime, I'll split one of these blades for a quick go.
When describing a blade we often drop straight into sharpness and smoothness, and perhaps post-shave feel. I like to consider the essence of the blade. So, for me, the Treet Platinum is consistent; the Treet Black Beauty, retro; Derby, legacy. What's this blade, then?
Comfortable and forgiving.
I'm a pusher. I inevitably end up using too much pressure and often find myself vocally suggesting to myself that I back off a little. Often we get just a little warning, or worse, a little bite when we press too hard. With this Shark, I could be quite lazy. It shaved well, comfortably and didn't feel the need to bite me when I paid it no heed.
But where does it stand amongst its peers?
Well, I think it's akin to SuperMax Blue Diamond or Treet Silver (which is actually a carbon blade, but more treated (treeted?) than the DuraSharp to feel much more like a Stainless). In fact, next shave I'll use a Blue Diamond to compare on roll straight on into a EuroMax after that, which is reputed to be SuperMax under a new brand. The Shark is a real middle of the road blade. It shaves, it shaves well. It's not especially sharp and not noticeably smooth, but it is ... a nice middle of the road blade.
Again, lovely! I really enjoyed this shave in my benchmark Gillette Tech (a late model, 1980s perhaps) and tomorrow, I'll try it in something a little more aggresive: a brassy 1940s flat bottom Gillette Tech; then, a 1930s Gillette New.