New to Admiral CPVs

A Constant Plate Variety (CPV) is an error in the design that appears in only one position of a single plate. It is “constant” because it occurs each time that particular plate is used to print a sheet of stamps. It is not just a one‑off random error.

Examples include:

• Extra lines which map to other lines of the design.

• A noticeable thickening in part of the design.

• A dot or mark that always appears in the same place, but does not belong to the design.

If you can find a feature that matches one of our examples, you are looking at a CPV rather than a one‑off speck of dirt or improper inking.

• Defective transfers – problems when the design was first transferred to the plate, such as missing or incomplete detail.
  

• Re‑entries – places where the design was re‑entered on top of itself, leading to extra or doubled lines.
  

• Retouches – deliberate repairs or strengthening of weak areas of the design done on the plate.
  

• Plate flaws – damage, wear or other accidents that affected the plate during use.
  

On the home page, you will find short definitions and links to examples for each of these four types; that is a good place to spend a few minutes before you start serious searching.

Each Zone covers a small area of the design (for example, part of the value tablet, letters of CANADA, or part of the frame).

The Zones are numbered in a way that ensures each Zone applies to a unique area of the stamp.

When a variety is recorded, it is tagged with the Zone or Zones where it appears.

You can then search by Zone to find varieties that affect roughly the same area as the feature on your stamp.

If you are new to Zones, start with the Zone tutorial. It shows how the stamp is divided and gives simple examples. You do not have to memorize the system; you only need to be able to say, “my feature is roughly in this part of the stamp.”

Identify the denomination ( 1¢ Green, 2¢ Carmine, etc.)

Look at the feature:

• Is it a re‑entry, a retouch or a plate flaw?

• Does it affect letters, the frame, the portrait, or the background?

Locate the Zone:

• Use the Zone diagrams (from the tutorial) to decide which Zone or Zones best match the area where the feature appears.

Search the database:

• On the Primary Search page, select the denomination, a CPV type and the Zone. Applying more search parameters will significantly improve the search results.

• Run the search to see matching varieties.

Compare images:

• Click on a candidate in the search results.

• Compare your stamp with our images at high magnification.

• Look for the same shape, size and position of the feature, not just something “similar”.

If nothing matches exactly, it may be:

• A CPV we do not yet have recorded.

• A non‑constant one‑off error.

On this site:

• Some CPVs are already plated (the plate position is known and recorded).

• Some are clearly constant but not yet able to be assigned to a specific position.

• Some are tentative and need more examples to confirm them.

The database lets you:

• Use CPVs to narrow down likely plate positions.

• See which items are still “work in progress”, where additional examples would be helpful.

You can think of it as a shared working notebook for Admiral CPVs, built on Marler’s work and extended as new material turns up.

• Know every Admiral shade, perforation, or printing – as long as your stamp is a 1911 KGV Admiral, you can still use the images.

• Understand all of Marler’s terminology before you search.

• Recognise every CPV type at a glance.

If you can:

• See that your stamp has an unusual feature, and

• Point to the part of the design where it appears.

Then you can already make good use of the database.

The rest you can pick up gradually from the examples and references.

• Read the short CPV definitions and examples on the home page (Defective transfers, Re‑entries, Retouches, Plate flaws).
  

• Work through the Zone tutorial to get comfortable with the grid.
  

• Try the Primary Search with one or two of your own stamps.
  

• If you find something that might be new, check the “Is It Constant?” page and consider sending a scan.
  

Over time, you will find that the language and structure become familiar, and the site will feel more like a working tool than a reference book. That is exactly what it is meant to be.

• 
The quantities of Admirals produced were huge.

• Most Admiral printing plates had quite a short working life.

• The chances of finding a specific CPV are quite small.
  

For example, there are almost 70,000 different 1¢ green sheet stamp positions. The major re‑entry on the 1¢ green 12LR35 is rare: one could reasonably expect to look at many thousands of stamps before finding an example. (12LR35 means position 35 on the lower right pane of 100 from plate 12.)

There are additions to this site most weeks and many of those additions are newly reported CPVs.