Trail Die Obverse (TDO)

A Trail Die Obverse is a die variety where the obverse shows raised tendrils extending from design elements — typically from the corners of letters and numbers. These tendrils gradually narrow and fade out as they extend into the field. Trail die varieties are produced when a die is polished and affect every coin struck from the die after that polishing. They are sometimes called "trails" or "trail lines." The same thing happens on the other face, catalogued as Trail Die Reverse; the mechanism is identical and a coin can carry both.

How Does It Happen?

Trail dies are caused by careless die polishing. During die maintenance, a rotary polishing or buffing tool is applied to the die face, for example to remove clash marks or other surface marks. When these tools contact the die, soft bristles or felt fibers gather in the die's recesses — the incuse portions that form design elements like letters, numbers, and devices on the finished coin.

As the spinning polishing tool rotates, the concentrated fibers at these recessed edges erode a narrow gully into the field portion of the die face. This gully radiates outward from the corner of the design element where the fibers gathered. Because the gully is incuse on the die, it produces a raised tendril on every coin struck from that die.

In the July 17, 2017 Coin World, Will Brooks and photographer Ray Parkhurst set out several lines of evidence for the polishing explanation. Sean Moffat later reproduced faint trails experimentally by swirling fine diamond grit over a finished die with a rotating polishing tool for 20-30 seconds.

The key characteristics of trail formation:

1. Polishing origin: Trails are a byproduct of die maintenance, not the hubbing process. They can form at any point in a die's service life when polishing is performed.
2. Single tendrils: Unlike doubled dies that produce a second image of the design, trails produce individual raised lines extending outward from design element corners.
3. Gradual fade: Each tendril narrows and fades as it extends further from the design element, reflecting the decreasing erosion away from the concentration point.
4. Die defect, not striking error: Trails exist on the die itself and reproduce identically on every coin struck from that die.

Error-Ref notes that trails are seen on all modern U.S. coins, as early as 1921, and on foreign coins.

Discovery and Naming

Trails were not recognised as their own phenomenon until 2000, and the first example found was misattributed. In late 1994 John Wexler examined a Lincoln cent submitted by G. J. Lawson showing a strange bending of the Memorial steps beneath the columns. He concluded the column fluting had been replicated into the stairs and catalogued it as a doubled die, 1994P 1c WDDR-004.

It remained listed as a doubled die for six years. In June 2000 Kenneth Edgar submitted the same die to Ken Potter, who recognised it and was the first to note lines running from the bottom of the designer's initials (FG). He named them "trails" for the way they trailed off as they lengthened.

More evidence came in 2003, when Harold Kuykendall sent Potter a 2003 Lincoln cent with the same anomaly on a die produced by the single-squeeze hubbing process, which made a doubled die an unlikely explanation. Kuykendall had described the steps as "wavy" in his submission letter, and "wavy steps" became the accepted name for trails running from the columns into the Memorial steps. A third date, a 1999 cent, was identified soon after by BJ Neff.

On dates. Because trails were only recognised in the 1990s, documentation runs backwards as well as forwards: TrailDies.com reports more than 1,100 different dies from 1961 to the present, across cents, nickels, dimes, quarters, half dollars and dollar coins, while Error-Ref notes the effect on coins as early as 1921. An early date therefore reflects when the coin was struck, not how long the variety has been known.

Further reading: Will Brooks, "Unraveling the Mysteries of Trail Dies", Coin World Weekly, 17 July 2017.

Trails also occur on incuse devices, which are raised on the die rather than recessed. Here the buff or bristles concentrate against the raised wall and gouge a trail into the field where the device terminates. These trails are weaker, because there is no change in relief at that point to concentrate the fibres.

A single coin can carry several sets of trails running in different directions, and they vary in strength from naked-eye obvious to barely perceptible under magnification.

How to Identify a Trail Die Obverse

Trail die varieties have distinctive characteristics that separate them from doubled dies and machine doubling:

• Raised tendrils from corners: The hallmark feature is thin, raised lines extending outward from the corners of letters, numbers, or design elements. These tendrils originate at specific points — not broad doubling across entire design elements.
• Gradual narrowing and fade: Each trail line tapers and weakens as distance increases from the design element. The starting point is strongest; the end is barely perceptible.
• Consistent across the die: All affected areas show trails emanating from the same types of features (letter corners, serifs, number endpoints) because the polishing action follows the same mechanical pattern across the die.
• Not a doubled image: Trail dies do not produce a second copy of a letter or device. They produce thin lines extending outward — fundamentally different in appearance from the full duplicate forms of a doubled die.
• No shelf effect: Unlike machine doubling, trail dies do not produce flat, shelf-like displacement. The tendrils have depth and dimensionality.

Trail Die vs. Doubled Die vs. Machine Doubling

Machine doubling takes several forms, and worn dies produce a look-alike of their own; Mechanical Doubling covers the whole family.

Notable Examples

Lincoln Cent Trail Dies

Trails were first recognised on Lincoln cents, and TrailDies.com keeps separate Lincoln cent listings for each decade from 1980 on, with die-specific photography. The best-known Lincoln form, wavy steps, is a reverse feature; on the obverse, look at the lettering and the date.

Jefferson Nickel Trail Dies

TrailDies.com lists Jefferson nickel trail dies from 1960 to 2020. Look at the lettering and date for tendrils running into the field.

State Quarter Trail Dies

Error-Ref illustrates an obverse trail die on a 2005-P California quarter (2005P(CA)-25DEO-001T in the TrailDies numbering), with trails running from UNITED STATES.

Kennedy Half Dollar Trail Dies

TrailDies.com keeps a separate listing for Kennedy half dollars. The large format of the half dollar makes trail features easier to photograph and study.

Collecting Tips

• Strength of trail: Trails vary from naked-eye obvious to barely perceptible under magnification. TrailDies.com grades the Lincoln wavy steps and fluting-line trails by how far they reach (weak, moderate, strong, very strong) and notes that line intensity counts as well as length.
• Attribution resources: TrailDies.com maintains a catalog of trail die varieties with photographs, numbered by date, mint, denomination and side (DEO for obverse, DER for reverse, with T for trails and WS for wavy steps). Cross-referencing a suspected trail die against it is the way to attribute one.
• Photography technique: Trail dies photograph best under low-angle directional lighting that emphasizes the raised tendrils. Lighting perpendicular to the trail direction produces the most dramatic contrast.
• Die state matters: Early die state coins show the crispest trail features. As the die wears through its production run, fine details including trail tendrils become progressively weaker. Conversely, trails can also be introduced during mid-life die polishing.
• Related defect — wavy steps: Wavy steps are trails that run from the columns into the Memorial steps on Lincoln cents, giving the steps a wavy look.