1968-S Lincoln Memorial Cent Doubled Die ?

Figures #1 and #2 are strike/mechanical doubling.

okay, okay machine.

So, I'll stay with Strike Doubling from now on.

Still, damage is damage.

Yes, and proper terminology is proper terminology - especially in a learning environment. And it's not all Strike Doubling, but it is all Machine Doubling.

I was only correcting errors in terminology. Would YOU want to be taught using improper terminology?

Hi Chuck:



What's the difference between Strike Doubling & Machine Doubling?

I've seen slabbed coins being sold on E-bay stating Strike Doubling

I thought Strike Doubling usually happens on Proof coins since they are hit twice.

Three common forms of Machine Doubling:

Strike Doubling - also called die chatter - when a die bounces during a single strike, flattening parts of the devices into the field. causes a flat "shelf-like" doubling atop which rests the design of the field next to it. Any die scratches, etc., that were on the field adjacent to a letter will show a second time on the 'doubling'.

Eject doubling - happens when a coin sticks to a die and is forcefully pushed out of the way. It 'scoops up' the sides of the letters, often leaving shiny striations going 'across' the doubling. Also commonly leaves a raised 'fin' on the tops of the letters where the extra metal from the 'scooping' effect is left behind.

Die Deterioration Doubling - happens when the edges of devices start to chip away due to die age. Shows as raised rough edges that look like hub doubling in some ways, but almost always affect both sides of letters.

All of these are ' Machine Doubling' but have very different appearances when studied closely.

Machine Doubling is to 'vehicle' what each of the aforementioned are to 'truck', 'car', 'motorcycle'. Similar but very different, and there's one encompassing very general term to describe them all.

I quit uzing 2x2s years ago, but I still write in pencil on my flip inserts. I recommend flips every chance I get, and this is one of those chances.

Even though archival flips cost around a nickel each as opposed to the 2 cents each that 2x2s cost, there is a certain amount of freedom in having all the information on a coin written on a piece of paper that is completely independent of the part where the coin is stored. If you goof, just cut another piece of paper.

Additionally, flips don't require staples and 2x2s do, making them extremely hazardous to the coin if the coin is to be removed later.

And third, if you don't flatten your staples (what a pain in the rear), you'll stretch out and put bumps in the pockets in your pages. Flips don't do this.

Need more? Stacking 2x2s always leaves you open to the possibility of scratching one coin with the staples in the next coin's holder. Flips are sooth, don't have staples, thus eliminate this danger.

Now remember - DO NOT buy flips that are soft and bend easily or smell like plastic shower curtains. Those have PVC in them and spell out death to your coins. Get flips that are crisp and hard and have no smell. Those are mylar, which do not contain PVC. They are usually advertised as "archival safe".

Last thing...get flips that have rounded corners and are pre-cut. The flips that come in sheets often have square corners and are a pain in the rear to put in pocket pages.

Let me know and I can mail you a couple of examples of what I use.

If you move over to flips, you'll be grateful you did.

Let's just say that if I had a nickel for every machine doubled coin I've seen, attributed, or answered a question about, I would never have to work again.

Flips really are much better and much more practical, but if you're set on 2x2s, be well with it. Just be very careful when removing coins from those.