The Cavanagh Edge The Hatted Professor in his 1920s Dobbs Derby

Edge of Distinction

The Cavanagh Edge is surely the classiest brim treatment yet applied to a hat. Also known as a hand-felted edge, it is essentially a welted edge that is an integral part of the felt, and not stitched down in its final form. Cavanagh’s goal was to create a lightweight hat without sacrificing brim strength. His patented process created a finished edge that not only added more strength to the brim than that provided by either the bound edge or the welted edge, but also had very clean lines, with no exposed stitching or gap where the welt had been ironed over onto the brim. While mainly intended for soft hats, Cavanagh also saw that it could give a Derby or Homburg a nicely finished edge.

In some ways, Cavanagh’s invention was almost a step backward, as most inventions for hat-manufacturing involved ways to increase mechanization to reduce labor costs and increase efficiency and output. While the other brim edge treatments are applied during the final finishing stages of the hat, creation of the Cavanagh Edge begins during the felting process of the hat body, and continues throughout the entire production process. Each step in the process added to the labor and cost of a Cavanagh Edge hat, resulting in a premium feature for premium hats at a premium price.

Genesis of the Cavanagh Edge

At the time John Cavanagh first started working on the Cavanagh Edge process, there were three basic types of brim edge treatments applied to hats. The first was the raw edge, where the brim was trimmed to size, with no extra appointments added. The second was the bound edge. On hard felt hats, such as the Derby, the edge of the brim needed to be bound in ribbon to keep the white residue of the shellac from showing through. Third was the welted edge. Welted edges were used to add strength to the edge of the brim of soft felt hats, which had been soaring in sales since Cavanagh recommended their reintroduction in 1906. The stitching on welts was a weak point, and not as attractive as Cavanagh would have liked. The intimate knowledge of brim edges that he gained from his job, as well as the knowledge of felt passed along by Knapp, enabled Cavanagh to perceive a solution to the deficiencies of bound and welted edges, a solution that would come to be known industry-wide as the Cavanagh Edge.

The Process

As with any hat, the fur was blown into a cone until the large, fragile body, or hood, was ready for felting, or “sizing” where the cone is shrunk down and condensed into felt. The size of the cone selected for the hood determined headsize, crown height, and brim width. Unlike a normal felt hood, which can accommodate finished hats with variations in headsizes, crown heights, and brim widths, a hood with a Cavanagh Edge was made exactly to a specific hat size, crown height, and brim width from the very beginning of the process. In the early stages of felting, it was possible to obtain three or four different sizes of finished hat, but once the felting was in the final stages, only one or two sizes were possible.

The felter interrupted the felting process once the cone had felted enough to hold a welt edge. At this point, the cone was about 20 inches in height, very lightweight and soft, feeling much like a fleece blanket. The felter cut the bottom of the cone to the proper size to make an even edge. Before sewing the welt, the fur needed to be prepared by running carding cloth along what would become the inside of the welt. Carding cloth has tiny metal teeth imbedded in it, which rakes and loosens the fur fibers from the felt, causing them to stand up. This loose fur allowed the welt to felt back onto itself, ensuring a strong, integrated welt. An inch of the edge was then folded over and stitched down using a sewing machine with a special guide designed for Cavanagh Edges.

The cone then returned to the felting process, which was carried out just as it would be for any other hat. Two-thirds of the way through the felting process, the thread holding the welt was removed. The impressions in the edge where the stitches used to be were obliterated during the remainder of the felting process, although the stitches could be left in, to become part of the felt. However, this was probably the less-used method. Either way, it explains why you might see either the remains or ghosts of stitches on a vintage Cavanagh Edge.

The newly born Cavanagh Edge was far from pretty, however, due to the unevenness of felting. Once felting was complete, the real process on the Cavanagh Edge began. The “Cavanagh Edge Process,” which C & K pushed in their advertising in the 1920s (indeed, it was even emblazoned across the front of their new factory in 1923), was about more than just the edge itself. During the process, the brims were worked entirely by hand in hot water, which made for tighter felt and imparted extra strength to the brim that could not be achieved in a regular hat felting process.

A shackle and hot water and cut the welt down to an even shape. This was one of the most labor-intensive actions in making a Cavanagh Edge, where skilled craftsmen earned their pay. The finished edge finally resembled the Cavanagh Edge we all know and love.

Cavanagh Edge hats were NOT flanged from the C & K factory, nor were the brims ever ironed. The curl you see in a Cavanagh Edge brim is there naturally through the process. Other factories may have used irons, as several were invented, and they may have flanged their own hats, but that I don’t know for sure. But flanges and irons weren’t used by the C & K factory.

Some hats received the Cavanagh Edge Process, and then had a ribbon bound over the Cavanagh Edge. This was mainly done on some Derbies and Homburgs. On some hats, the Cavanagh Edge was even cut off to make a raw edge, but with purportedly better strength because of the process. (Oh, the horror! Actually, I suspect these hats were rejects from the Cavanagh Edge Process, where the welt did not turn out as planned, but could be salvaged and sold anyway, hence the advertising of the Process on a raw-edge hat.)

1.  Loosely felted cone with the initial welt sewn down.

2.  Hood that has completed the felting process, with a wide, misshapen edge.

3.  Hat body that has been blocked and had the edge shaped by a shackle.

Three Cavanagh Edges

Three different patents were granted for the Cavanagh Edge. The first, granted in 1913, was the simplest to make, and the one most likely used on hats with hand-felted edges throughout the twentieth century. This is the process described above.

The second patent was issued in 1931. With the first patent expiring, and subsequently, any exclusive use of the process, and with the popularity of the Cavanagh Edge increasing, John Cavanagh came up with a second process that would theoretically improve the Cavanagh Edge and keep him one step ahead of the competition.

The second process differed only in that a thin strip of felt, with fibers running perpendicular to the fibers in the hat cone, was inserted inside the welt. This extra felt was purported to give added strength to the Cavanagh Edge during the felting process. This patent was put into production, at least for a while.

Second Patent Cross-section

The third patent, granted in 1935, resembled the second, with the exception of a rolled piece of felt yarn, which was placed inside the welt instead of a flat strip of felt. It is unknown at this time whether this patented process was ever put into production.

Third Patent Process, showing the felt yarn inside the welt

Unless marked on a hat’s sweatband, there is no way to tell which process was used to create a particular hat’s felted edge. While it would seem logical that the last two processes would create a thicker edge than the first, this is not the case. The size and shape of the edge is actually determined by factors such as the shackle used to shape the edge and the work the individual craftsman and finisher does on the brim. The author’s feeling is that, unless marked otherwise, it is probable that the first process was used, since it is the simplest and least labor-intensive.

Cavanagh Edge Nomenclature

Cavanagh Edges could be found on hats from Crofut & Knapp, Dobbs, Cavanagh, Knox, Dobbs, Stetson, Mallory, Resistol, Stack, Borsalino, Disney, Portis, Lee, Bond, Duff, and Stevens, just to name a few. Crofut & Knapp held the patent rights in 1913, but extended their exclusivity to Dobbs, a successful line of hats created by John Cavanagh in 1908. The creation of the Cavanagh line of hats in 1928 gave three brands the Edge. Crofut & Knapp does not appear to have licensed the process to any other manufacturers. With the expiration of the first patent by 1931, other manufacturers were finally free to offer their own version of the Cavanagh Edge, and the heyday of the felted welt edge really began.

At its most basic, the Cavanagh Edge is a felted welt edge, and this is the term first marketed by Crofut & Knapp. It wasn’t until the 1920s that edge came to be known as the Cavanagh Edge. Over the years, many different names have been applied to it by the various manufacturers. Dobbs, for example, has given it the names Felted Welt Edge, Cavanagh Edge, Improved Cavanagh Edge (the second patent process, also marketed as the Cavart Patented Process), Guild Edge, and Dobbs Edge. Dobbs also offered a hand-finished Cronap Edge, in the 1930s in addition to the Cavanagh Edge, but the author is uncertain at this time as to what edge it represented. The name Guild Edge was first marketed in 1944, and is the name best associated with Dobbs.  In Cavanagh Hats, it has always been the Cavanagh Edge.

1930s Dobbs with Improved Cavanagh Edge

When Knox introduced their version in 1931, they named it the Custom Edge, a name they continued to use throughout the rest of their production. Stetson used the name Selv-Edge in 1933, but by 1940 changed it the Mode Edge. Mallory gave it the name Duplex Edge.  Borsalino referred to their edge informally as the Bordo Doppio, or “double edge.” Stevens called it the Hand-Felted Edge. Lee called theirs the Edgelee.


The success of the Cavanagh Edge led competitors to imitate the style while trying to avoid the extra labor and expense. Various improvements on welt edges were developed over the years, and quite a few used concealed stitching. An underwelt with concealed stitching, where the thread does not break through to the topside of the brim, made for a good poor man’s Cavanagh Edge, at least when viewed from the top or front. Concealed stitching options were attempted with both overwelts and underwelts, as well.

Imitation of Cavanagh Edge Using a Concealed-Stitch Underwelt

A bonded, or "stuck edge," where the welt was fixed with adhesive rather than thread, was another option. The welt was first glued down, and then stitched. Once the glue was set, the stitches were removed. After the welt was pounced, no traces of the stitches remained. This method revived the Cavart name in mid-1973 as the Cavart Edge in Cavanagh hats, though it was not related to the earlier Cavart Patented Process.

Some tried to improve upon Cavanagh’s ideas. In 1917, one hand-felted imitation used a strip of felt cut from the bottom of the cone, which was then folded over the bottom edge, so that an equal welt would be formed on both sides of the brim, instead of just the top. Interestingly, Cavanagh included this as an optional step on his second patent. Other patented variations of this included using a strip of felt that was a contrasting color from the rest of the hat body, so that the edge would have a two-tone effect.

Others inventors came up with novel ways of making an edge that had the appearance of the Cavanagh without the costly extra labor involved in the felting process. In 1932, George McKinnon patented for Stetson a reasonable facsimile of the edge that did away with the welting steps during felting, though it did involve specialized equipment. Marketed as the Re-Enforced Edge, it was created when the fur was blown into the cone, where a channel along the bottom of the cone collected extra fur to make a thickened edge as an integral part of the felt cone. Frank T. Stack, plant superintendent for Hat Corporation of America, head of Stack Hats, and four-time mayor of Norwalk, invented a two-piece iron that forced the felt along the edge of the brim into a groove during the ironing process, thereby creating a beaded edge during the finishing process. None of these imitators ever achieved the success of the original Cavanagh Edge, and so companies continued to produce the Cavanagh until its demise.

Edge of Extinction

Cavanagh Edges died out partly from their cost. Because the production and finishing was far more labor-intensive and required more fur than regular bodies, a hat with a Cavanagh Edge cost at least twenty percent to fifty percent more than a typical hat and remained relatively rare. One estimate places the number of hats produced with Cavanagh Edges at two to three percent of total hat production. Hats with a Cavanagh Edge were therefore marks of distinction for discriminating buyers, prized for their scarcity, durability, and simple but elegant beauty. Along with the overall decline in hats sales, buyers became less discriminating, opting for hats with imitations of the Cavanagh Edge, or forgoing them altogether.

Hat Corporation of America closed their Norwalk factory in 1970, moving their remaining hat production to Winchester, TN. In 1972, they sold their brands to Koracorp, owner of Resistol among other brands, in Garland, TX, where hats are still made to this day. No one knows when the last Cavanagh Edge was produced, but they were still being offered in 1983. They probably did not last much longer than that, however.

Few hatters today know how to work with Cavanagh Edged bodies, and fewer still is the number of felters that remember how to craft one. It is arcane knowledge from a bygone era. While hat making has not died off completely, certain techniques, such as the Cavanagh Edge, are virtually extinct. Felters and manufacturers have been pursued, cajoled, and even offered large sums of money to revive this lost art, but the answer keeps coming back a resounding, “No.” The option is always there, though. The concept is fairly simple, but the execution requires much skill and effort. For now, the Cavanagh Edge may be dead, but the process created by the master, John Cavanagh, will forever live on in the vintage hats that bear his edge of distinction.

~The Hatted Professor

© 2016 J. Bradford Bowers


The Hatted Professor in his 1920s Dobbs Derby

The History of Crofut & Knapp, Dobbs, and Cavanagh Hat Manufacturing

The Hatted Professor

The Cavanagh Edge

The Hatted Professor

The Cavanagh Edge
Contact the Hatted Professor
The Hatted Professor

The Hatted Professor

The Cavanagh Edge
Contact the Hatted Professor
The Hatted Professor