1907 Ultra Thin Planchet Large Cent - Ideas?

with acid too--I've seen a few, although not this particular series.
The wiry rims and skinny, sharp-edged legends strongly suggest the work of acid--imo.
I don't think a planchet half the normal weight would strike up so equally

If you want to try something that many of us did as kids, just put a large cent (or small one) in a small glass of regular Coaca-Cola (if it still has the same formulation). Seal the top so that it can't evaporate and watch the coin disolve like this one has partially. The side that stays touching the bottom of the glass will either have much more or much less "burn-off" (I can't remember which had the most/least). The coin will still have esentially the same amount of relief that it started with over most of the coin, because the high points and flat fields will eat away at the same rate. The rate will be a thinner, lighter coin with almost as much detail until the end of the experiment .. then it will dissolve altogether. I even did it with a spoon one month .. it takes a while so it's not instantaneous. I think that the 1907 had the acid or solution actually brushed or applied to each side intermitantly .. you normally will get a fully submerged one to get the edges eaten away as well.

I also have found a Canadian thin planchet, Edwardian large cent. Mine is dated 1910 and is the same exact diameter as a regular issue but about 1/2 the weight and thickness. It also seems to be rim-less with the denticles reaching the coin's edge. The fields behind the bust do seem to have some miniscule pitting that would give credence to the acid theory, but I would like to think it's a thin planchet that got mixed in with the others at strike-up time. Wm

before I even read the other's comments I thought acid etched (more so on the bust side)

It is amazing how often acid treated coins appear on ebay and forums. Mostly labeled as struck on foreign or thin planchets. Once you learn to recognize the type, they can be spotted a mile away. They all have that fuzzy detail look, are usually much thinner than a normal coin with surfaces that are somewhat pitted. If you search ebay with the word thin, several examples will always show up. I wish I could round them all up and bury them. I hate to think how much money people lost on these but we all have had some hard lessons, I guess some harder than others.

, pennysaver!

Diameters should be slightly smaller. They may just not have noticed. If acid was beaded up on the surface, rims would not be affected.

On the diameter question, I think you need to take surface area into account. There is an awful lot more Obv and Rev than there is edge. You would notice the effects (planchet thinning) sooner then you would on the edge (reduction in diameter).