Since I started collecting, I’ve solely focused on black colorways. However, something about clear and frosted designs have spoken to me… Plus I had inadvertently accumulated quite a few in my collecting journey.
How do you prefer to describe these? Clear, demonstrator 
, or skeleton 
?
Also, please feel free to share some of your favorites!
Clear Pentel S15 in there?
Awesome collection. Usually they are called demonstrators
Yes! One I found at a 90 year old stationery store in Bangkok.
Ah, that’s right.
I like the frosty P205 best.
My fave here had to be the clear Zebra Tect with the magenta grip rings. when I found mine, it kind of surprised me that the low tier, “self-cloned” Tect would get this much love from Zebra.
My own fascination with demonstrators or skeleton pens began with my childhood Pilot H-227, which I have kept to this day, cracks and all. All I have to say is: it doesn’t take much to veer off into pen and rollerball territory! Happy collecting!
I like clear Dr Grip Ace, Flexfit 2 and S3. Have the Olno, love it!
What follows will probably sound unnecessarily hairsplitting, but I would still separate the perfectly transparent models (actual “demonstrator“ in the historic meaning of the term) from the “frosty”/translucent ones: the latter family still sports a shade of colour, albeit a very faint one, whereas the purpose of a true demonstrator is to show the internals with the most minimal interference possible offered by a non-carved (or otherwise pierced) barrel.
Still, pretty impressive array of fine pencils. 
PS: “Skeleton pencils” is truly a great name: I have seen it used for clocks (“skeleton clocks” make for a super-cool niche of horology, of interest per se), and I know that in old graphics studios they would call “X-ray drawings“ or “Röntgen representation“ those drawings with the outer walls of any volume made transparent to show the internals — worked for anything from cars to houses, from electronics to engines — but we should really petition for a larger adoption of the expression “skeleton MP’s“ in the pencil world.
Agree 100% @Leonov
Hairsplitting is why I love this community and forum!
But yeah, I agree with you. And within the totally transparent, demonstrator category, I would divide them further into ones that sport colored internals and those that have the internal mechanism on full display devoid of any other adornments.
I had a ‘Internet Argument’ on Reddit recently over the latest Lamy Safari ‘Vista’ demonstrator. A very insistent person said it was redundant for the ‘rotation window’ to be molded into the clear shell, and that the color of the KT logo inside should have been the same as the normal versions. There’s no winning this 
That reminds me of a plastic model kit from when I was a kid: the Visisble V8" a battery operated working model of a V8 motor with a clear plastic “exterior” so you could watch the pistons and the cam shaft go …
