Planchet errors
Blank Planchets: Type 1 vs Type 2, and How to Tell a Real One
A coin with no design at all looks like the simplest error there is. In practice, "blank" pieces cause more confusion than almost any other category, because a worn-smooth coin, a sanded coin, a washer, and an arcade token can all look blank at a glance. This guide explains what a genuine unstruck blank is, how the two recognized types differ, and the short list of checks that separates them from imitations.
Quick answer
- A Type 1 blank is a disc as it came out of the blanking press: no raised rim, edges slightly rough or sheared.
- A Type 2 blank (often just called a planchet) has also passed through the upsetting mill, so it has a raised rim and a slightly smaller diameter than a Type 1.
- A genuine unstruck blank has a plain edge and no design traces. Reeding, lettering, or ghost design near the rim means the piece was struck or is an altered coin.
- Weight should land near the normal weight for that denomination and composition. A blank that is far too light is usually a ground-down coin.
- Weigh, measure, inspect the edge under magnification, and compare to certified examples before you call it a blank.
How blanks fit into coin production
Every coin starts as metal strip. A blanking press punches round discs out of that strip, leaving behind the perforated "webbing." Those discs are then treated (softened by heating, cleaned, and dried) and run through an upsetting mill that squeezes the edge and raises a rim. Only after that do they head to the coining press, where the dies and collar give them their design and edge.
A blank error happens when a disc escapes the process before it is struck. Because the striking stage is where the design, the reeding, and the final diameter come from, an unstruck piece carries a recognizable set of features. Learning those features is the whole game. If you want the wider map of where planchet errors sit next to die and striking errors, our overview of mint error types lays out the three families.
A note on vocabulary. Some collectors say "blank" only for the Type 1 disc and "planchet" only for the rimmed Type 2. Others use "blank planchet" for both and add the type number. Labels from grading services usually spell out the type, so it pays to learn both systems.
Type 1 vs Type 2: the side-by-side
| Feature | Type 1 blank | Type 2 blank (planchet) |
|---|---|---|
| Stage it escaped | After blanking, before the upsetting mill | After the upsetting mill, before striking |
| Rim | None; the face runs flat to the edge | Raised rim on both faces |
| Edge | Can show a sheared band and a rougher fracture band from punching | Smoother, rounded from the squeeze of the mill |
| Diameter | Slightly larger than a Type 2 of the same denomination | Slightly smaller; upsetting pulls metal in toward the rim |
| Thickness at edge | Even across the face | Thicker at the rim than at the center |
| Reeding or lettering | None | None |
| Design traces | None | None |
The rim is the fastest tell. Lay the piece flat and look at it edge-on at eye level. A Type 2 has a visible lip around both faces; a Type 1 looks like a flat washer without a hole. Under a loupe, the edge of a Type 1 often shows the two-zone texture you get when a punch shears through metal: one smoother burnished band and one rougher broken band.
The five checks that separate real blanks from fakes
Most "blank coin" listings are not unstruck planchets. They are coins that were worn smooth in circulation, ground or sanded, dissolved with chemicals, or they are not coins at all. Run these checks in order and write down each result before you decide anything. Our post on writing observations before attribution explains why that order matters.
- Look at the edge first. Reeding and edge lettering come from the collar and edge process during or around striking. An unstruck blank should have a plain edge. A smooth-faced piece with reeding is not an unstruck blank, full stop. It might be a heavily altered dime or quarter, or a different error entirely, but it is not what the seller is calling it.
- Weigh it on a calibrated scale. Striking moves metal around but does not remove it, so a genuine blank should weigh close to the normal coin of that composition. Grinding and sanding remove metal, so altered pieces usually run light. Check your scale against a known reference weight before you trust a reading; our scale calibration routine takes a few minutes.
- Measure the diameter with calipers. Compare it to a normal struck coin of the same denomination. A Type 2 should land very close. A Type 1 should be a little larger. A piece that is noticeably smaller than both was probably ground down around its edge.
- Inspect the faces under magnification. Genuine blanks show a fairly uniform surface, sometimes with small nicks from tumbling around in bins. Altered pieces tend to show directional scratches from sanding, a pitted or etched look from chemicals, or faint remnants of letters and date near the rim where the grinding missed.
- Check the composition clues. Clad blanks are punched from layered strip, so the edge shows the copper core stripe just like a normal clad coin. Copper-plated zinc cent blanks should be plated all over, including the edge. A piece whose color or edge construction does not match the composition for the denomination needs a closer look; remember that color alone proves nothing.
Watch for non-coins. Arcade tokens, washers, foreign blanks, jewelry findings, and metal slugs turn up in rolls and coin jars constantly. If the diameter, weight, and thickness do not all line up with a US denomination, you are probably looking at something that never went near the Mint.
Smooth coin, sanded coin, or real blank?
Three kinds of featureless discs show up again and again. Here is how they usually differ.
Worn-smooth coin
Usually old and heavily circulated. The rim is worn low and rounded, the weight is a little under standard, and you can often find faint letters, a date outline, or edge reeding if you tilt it under raking light.
Ground or sanded coin
Directional scratch lines across the faces, an uneven or flattened rim, light weight, and sometimes a reduced diameter. The edge may still carry reeding.
Chemically erased coin
Dull, porous, or etched texture. Plated coins may show the underlying metal in patches. Weight usually low. See our comparison of missing clad layer errors vs acid-treated coins.
Genuine unstruck blank
Plain edge, consistent surface, weight near standard, diameter matching its type, and composition consistent with the denomination.
Blanks that also carry another error
Unstruck planchets sometimes have their own planchet problems layered on. A blank can be clipped, laminated, or cut from the wrong stock. These combinations need the same careful reasoning you would use on a struck coin.
- Clipped blanks. A blank with a curved or straight missing section. On a Type 2, look for the rim fading out near the clip, the same effect collectors use on struck clipped coins. Our post on clipped planchets covers the diagnostics.
- Wrong-stock blanks. A disc that is the right diameter for one denomination but the composition or thickness of another. These are evaluated with weight, thickness, and composition evidence, as described in our guide to wrong planchet errors.
- Laminated or flawed blanks. Flaking or split metal on a blank follows the same logic as on a struck coin; the key question is whether it happened during production or from damage afterward.
How to research a blank's value without guessing
We do not quote values here, and you should be cautious of anyone who quotes one without seeing the piece. What you can do is build your own evidence file.
- Search sold listings, not asking prices. Filter for the same denomination, the same type, and certified examples when possible: sold certified blank planchets on eBay.
- Compare like with like. A Type 1 and a Type 2 of the same denomination are not the same item, and a clipped or off-metal blank is a different item again.
- Note composition. Blanks for different eras and alloys of the same denomination are tracked separately by serious collectors.
- Check auction archives from established numismatic auction houses for certified examples and read the lot descriptions; our auction archive spreadsheet shows a simple way to log what you find.
- Remember that an asking price is not a value.
The factors that move interest in a blank are the ones you would expect: type, denomination, composition, surface condition, whether it carries a second planchet error, and whether a recognized grading service has certified it.
Tools and where to look
For blanks, the important tools are boring and cheap: a scale that reads to a hundredth of a gram, a set of digital calipers, and a 10x loupe for the edge. If you hunt rolls regularly, these three tools settle most blank questions in under five minutes.
When you browse listings, prioritize pieces with edge photos and a stated weight. A listing with one face photo and no weight is giving you very little to work with, as we explain in the one-photo error coin problem. If you want to see how certified examples are presented, search for certified blank planchets and study how the holders describe type and composition.
Frequently asked questions
Is a coin with no design always a blank planchet?
No. Most featureless coins found in circulation are worn, ground, or chemically erased coins, or are tokens and washers. A genuine unstruck blank has a plain edge, near-standard weight, and a diameter consistent with its type.
Why is a Type 1 blank bigger than a Type 2?
The upsetting mill squeezes the edge of the disc to raise a rim, which pulls the edge inward slightly. A Type 1 skipped that step, so it keeps the slightly larger diameter it had when it was punched out.
Can a blank planchet have reeding on the edge?
An unstruck blank should not. Reeding is formed by the collar during striking, so a smooth-faced disc with reeding has been in a coining press or is an altered coin.
Should I get a blank planchet certified?
Blanks are easy to imitate, so if you plan to sell one or if it carries an unusual feature such as a wrong composition, certification from a recognized grading service adds confidence for buyers. For an ordinary find, research sold certified examples first and decide whether the fee makes sense.
The bottom line
Verdict: For most finds, the edge and the scale tell you nearly everything. A plain edge, a weight near standard, a diameter that fits Type 1 or Type 2, and a surface without directional sanding marks add up to a credible blank. Anything with reeding, design ghosts, or a light weight belongs in the "altered" pile until proven otherwise. When a piece looks unusual, document it with full edge photos and get a professional opinion before you buy or sell.