Hi there. I've got a Preciso, too. The other day I was messing around with a kitchen strainer, using it to sieve my press grind (setting #34F, if it matters). I don't know how big the spaces are in the metal mesh, but a 1000 micron (1.0 mm) steel ball bearing doesn't quite fit through them, so it's probably close to what you asked for. Anyway, I gave 21.9 g. of my press-ground coffee a thorough shaking using this strainer and ended up with 20 g. of ground coffee remaining. That's only 8.7% loss. Not bad, right?

What was sieved out:



A closer look:



Bottom of the cup brewed afterward in my Eva Solo 0.6 L (damn, I missed a few fines!):

Right, the new Virtuoso has the same burrs as the Preciso, so it should perform similarly. In fact, I don't ever use the Preciso's micro adjustment lever for non-espresso brew methods. I've only sieved my coffee that once, so I'm no expert, but I thought it did give the coffee I brewed with it a slightly cleaner flavor profile; not sure it was cleaner in a *good* way though. If and when OE's Lido hand mill comes out, I plan to sieve again and compare its press grind to the Preciso's.

Will be interesting to see what happens. There's "good for a hand grinder" and "just plain good." How does the older Virtuoso compare to, say, your Peugeot hand mill with respect to coarse grinding?

Oh, I was just thinking out loud, and I know you've owned and tried both of the ones I mentioned. I don't particularly relish the idea of traveling with my Preciso! What's the best travel grinder for press these days? Maybe the OE-PFP, though I haven't played with one. I'd imagine OE expects the Lido to surpass it.

Just a quick follow-up to report that I got my hands on an old #20 testing sieve in mint condition (shown below). It does a nice job of filtering out particles below 0.85 mm. When I ground 20.1 g. of coffee using the same setting as before on the Preciso (#34F) and sieved it, I was left with 16.8 g., i.e. 16.4% loss. So, the strainer I'd been using before must have finer mesh.