Trail Die Reverse (TDR)

A Trail Die Reverse is a die variety where the reverse of a coin displays raised tendrils extending from design element corners — particularly letters, numbers, and fine devices. These tendrils gradually narrow and fade as they extend into the field. The mechanism is identical to a Trail Die Obverse, but the affected die is the reverse, and a coin can carry both. Trail dies are produced during die maintenance and affect every coin struck from the affected die.

How Does It Happen?

The reverse die is polished in the same way as the obverse die. According to TrailDies.com, trails form when a die is polished on a rotary tool: the buff's soft fibers or bristles work down into the die's recesses (the sunken areas that strike letters, numbers and devices), collect in their corners, and wear a groove into the die as they climb out onto the higher field.

Those grooves start at the corners of letters, numerals and devices and run out into the field. Because they are sunk into the die, they strike up as raised lines on every coin made from it.

The cause is the same on either die:

• Buff fibers or bristles collect in the corners of design elements during rotary polishing
• The tool wears grooves that run outward into the die's field
• Trails are strongest where the device meets the field and taper as they extend
• The grooves show as raised lines on the finished coin

This polishing explanation is the one given by TrailDies.com and in Will Brooks's 2017 Coin World article. Wikipedia's entry instead describes the cause as unknown and believed to be movement of the die against the hub during single-squeeze hubbing; the specialists who catalog trails favor polishing.

Reverse designs differ a great deal from one series to another, so where trails show up differs too. TrailDies.com's reverse listings describe trails from lettering such as DIME, STATES and E PLURIBUS UNUM, from the flames of the dime's torch, and from state-specific text and devices on state quarters.

Discovery and Naming

Trails were not recognised as their own phenomenon until the mid-1990s, 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 took the bent steps to be the column fluting copied down into the stairs, and listed the die as a doubled die, 1994P 1c WDDR-004.

It remained listed as a doubled die for six years. In June 2000 Kenneth Edgar sent the same die to Ken Potter, who recognised it and became the first to point out lines coming off the base of the designer's initials (FG). Potter called them "trails" because they faded out as they got longer.

The case against doubling grew in 2003, when Harold Kuykendall sent Potter a 2003 Lincoln cent with the same anomaly on a die made by single-squeeze hubbing, a process that makes hub doubling unlikely. 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's running tally stands at 1,691 dies (522 obverse, 1,169 reverse), across every circulating denomination from the cent to the dollar, mostly from 1961 on; older dies have been attributed after the fact, such as two 1921-S Morgan dollar reverses with trails running from the denticles. 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, the parts of a design that stand up from the die face instead of being sunk into it. Here the buff or bristles bunch up against the raised wall and cut a groove onward from the point where the device ends. These trails are weaker, because there is no step down in relief at that point to concentrate the fibres.

A single coin can carry several sets of trails running in different directions, and their strength ranges from plain to the eye to faint even under a glass.

How to Identify a Trail Die Reverse

The diagnostic features of a TDR mirror those of a TDO, applied to the reverse:

• Raised tendrils from corners: Thin, raised lines extending outward from the corners of letters, numbers, or design devices. These are single lines, not doubled images of the design elements.
• Progressive fade: Each tendril narrows and weakens as distance increases from the originating design element.
• Consistent direction: Trails from one polishing pass run in the same direction, and TrailDies.com records an offset direction in degrees for each die; a die polished more than once can show sets running in different directions.
• Not a second image: Trail marks do not reproduce the shape of the design element — they produce individual lines extending outward. This fundamentally distinguishes them from doubled die reverses.

Reverse-Specific Considerations

Reverse trail dies present identification challenges that differ from obverse trail dies:

• Polish lines: Ordinary die polish lines are scattered across the field. Trails start at the corners of design elements and taper away from them.
• Lettering: Reverse lettering (UNITED STATES OF AMERICA, E PLURIBUS UNUM, the denomination) gives the clearest places to look; many TrailDies.com reverse files are described from the letters.
• Leaves and devices: Leaf tips and device edges can also throw trails, as on dime reverses where TrailDies.com notes light trails from the olive leaves.

TDR vs. DDR 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 Reverse Trail Dies

The Lincoln Memorial reverse (1959-2008) is where trails were first noticed, and trails running from the columns into the steps are the "wavy steps" described above. TrailDies.com's Lincoln cent files run from 1981 onward and list hundreds of reverse dies, with dozens for single dates such as 1993-P, 1994-P and 1999-P.

Roosevelt Dime Trail Dies

TrailDies.com lists Roosevelt dime reverse trail dies including 1994-D (trails from DIME), 1996 (from STATES), and 2004 and 2011-D dies with trails from E PLURIBUS UNUM, the torch flames and the olive leaves. The small size of the dime calls for magnification.

Washington Quarter Trail Dies

TrailDies.com lists reverse trail dies on the eagle reverse of the 1990s and on many state quarter reverses, for example 2001 North Carolina (from FIRST and UNUM), 2004 Florida (from FLORIDA) and two 2007-D Wyoming dies with trails from THE EQUALITY STATE, WYOMING and the cowboy.

Morgan Dollar Trail Dies

The oldest reverse trail dies in the TrailDies.com files are two 1921-S Morgan dollar reverses, with trail lines running from the denticles; one is the die attributed as 1921-S VAM-1L.

Collecting Tips

• Check both sides: Some die pairs carry trails on both the obverse and the reverse, so examine both sides of any trail die coin.
• Where to look: Trails are easiest to see coming off lettering and sharp device corners.
• Magnification: Many trails are only visible under a loupe or stereo microscope with good, angled lighting.
• Attribution: TrailDies.com assigns file numbers (for example 1994D-10DER-001T: date and mint, denomination, DER for a reverse die, file number, T for trails) and records die markers for each die. It has suspended new attributions for now.
• Die markers for confirmation: Each trail die comes from a specific die, and that die has unique markers (die scratches, polish lines, minor die chips) that confirm attribution. Learning to identify die markers is essential for serious trail die collecting.
• Related defect — wavy steps: Wavy steps are trails that run from the columns into the Memorial steps on Lincoln cents.