Thank your deity of choice – my military-issued glass lenses were so heavy that I got blisters on the bridge of my nose!
The letter “W”. It’s NOT double-U, it’s double-V.
Can you hand me that roll of tin foil? Can you hand me a box of pencil leads for my mechanical pencil?
Baby powder?
Measuring square should be measuring triangle.
A telescoping antenna is not made out of telescopes.
When you “tickle the ivories”, the piano keys are probably plastic.
Film and tape. Declining in use, but not unheard of to say you have a film or tape of something when you may only have a digital copy. Also used as verbs.
Sailors’ oilskins were never made of skin, and today are rarely waterproofed with oil. (Although plastic is made from oil, so you could quibble about that.)
Yes, but the object is “roll” and “box,” not “tin foil” or “lead.” Miller makes a case that “a lead” is a thing, and I maybe buy that; but “a tin foil” ain’t.
A square is not a material.
A U is not a material.
A silver is not an object.
Ha ha! A powder is not an object.
Ooh, nice! “I saw a film” works really well.
Then the object was never named for the material.
I guess this is a harder concept than I thought!
At the large computer company I used to work at, before the use of PowerPoint and projectors, the transparency sheets used on overhead projectors were called “foils”. I never heard a good explanation why that was so.
I thought you were going to nitpick that the words don’t exactly refer to the material, but rather the structure of the material (i.e., a film of celluloid plastic). However, I was going to counter-nitpick that the same is true of glass, which refers to any amorphous solid and not a specific molecular composition.
I think people still use “mixtape” occasionally, even if it’s just a playlist on a streaming service.
How about silverware?
Not quite “material”, but I’m surprised people still refer to a single image from a PowerPoint presentation as a “slide”.
I did a lot of presentations, and it’s probably been thirty-five years since I loaded slides in a carousel (upside down, of course!) before I gave a talk.
It’s called a square because it has a square corner, ie a right angle. So it’s not a misnomer at all.
I would venture that it is a literal mistranslation from German, were Folie refers to a sheet, like in paper sheet or plastic sheet (bingo!), steming from Latin folium. Compare too transparency or viewfoil with Overheadfolie.
It is interesting that the English Wikipedia does not mention that the modern overhead projector was developed by Carl Zeiss in Germany, as the German Wikipedia claims.
I see my humor is wasted on you guys. 
We are the forever humourless.
We used to think that one’s temperament was a product of the proportion of various fluids in one’s body, but no we know that your humor is unrelated to your humors.
(I know, not an object…)
What is it? A concept?