Preserving Historic Signs

Historic signs can contribute to the character of buildings and districts. They can also be valued in themselves, quite apart from the buildings to which they may be attached. However, any program to preserve historic signs must recognize the challenges they present. These challenges are not for the most part technical. Sign preservation is more likely to involve aesthetic concerns and to generate community debate. Added to these concerns are several community goals that often appear to conflict: retaining diverse elements from the past, encouraging artistic expression in new signs, zoning for aesthetic concerns, and reconciling business requirements with preservation.

Painted sign saying “Bull Durham, Best for three generations” and a picture of a bull on the side of a brick building.
Signs for Bull Durham Tobacco once covered walls all over the country. Photo: Jack E. Boucher, HABS, NPS.

Preserving historic signs is not always easy. But the intrinsic merit of many signs, as well as their contribution to the overall character of a place, make the effort worthwhile. Observing the guidelines given below can help preserve both business and history.

Retaining Historic Signs

Retain historic signs whenever possible, particularly when they are:

  • Associated with historic figures, events or places.
  • Significant as evidence of the history of the product, business or service advertised.
  • Significant as reflecting the history of the building or the development of the historic district. A sign may be the only indicator of a building’s historic use.
  • Characteristic of a specific historic period, such as gold leaf on glass, neon, or stainless steel lettering.
  • Integral to the building’s design or physical fabric, as when a sign is part of a storefront made of Carrara glass or enamel panels, or when the name of the historic firm or the date are rendered in stone, metal or tile. In such cases, removal can harm the integrity of a historic property’s design, or cause significant damage to its materials.
  • Outstanding examples of the signmaker’s art, whether because of their excellent craftsmanship, use of materials, or design.
  • Local landmarks, that is, signs recognized as popular focal points in a community.
  • Elements important in defining the character of a district, such as marquees in a theater district.

Maintaining and Repairing Historic Signs

Maintenance of historic signs is essential for their long-term preservation. Sign maintenance involves periodic inspections for evidence of damage and deterioration. Lightbulbs may need replacement. Screws and bolts may be weakened, or missing altogether. Dirt and other debris may be accumulating, introduced by birds or insects, and should be cleaned out. Water may be collecting in or on sign cabinets, threatening electrical connections. The source of water penetration should be identified and sealed. Most of these minor repairs are routine maintenance measures, and do not call for special expertise. All repairs, however, require caution. For example, electricity should be turned off when working around electric signs.

More extensive repairs should be undertaken by professionals. The sign industry is a large and active one. Sign designers, fabricators and skilled craftsmen are located throughout the country. Once in danger of being lost altogether, gold leaf on glass and porcelain enamel are undergoing revivals, and the art of bending neon tubes is now widely practiced. Finding help from qualified sources should not be difficult. Before contracting for work on historic signs, however, owners should check references, and view other projects completed by the same company.

Major repairs may require removal of the sign to a workshop. Since signs are sometimes damaged while the building is undergoing repair, work on the building should be scheduled while the sign is in the shop. (If the sign remains in place while work on the building is in progress, the sign should be protected.)

Repair techniques for specific sign materials are discussed below (see “Repairing Historic Sign Materials”). The overall goal in repairs such as supplying missing letters, replacing broken neon tubing, or splicing in new members for deteriorated sections is to restore a sign that is otherwise whole. Recognize, however, that the apparent age of historic signs is one of their major features; do not “over restore” signs so that all evidence of their age is lost, even though the appearance and form may be recaptured.

Reusing Historic Signs

If a building or business has changed hands, historic signs associated with former enterprises in the building should be reused if possible by:

  • Keeping the historic sign—unaltered. This is often possible even when the new business is of a different nature from the old. Preferably, the old sign can be left in its historic location; sometimes, however, it may be necessary to move the sign elsewhere on the building to accommodate a new one. Conversely, it may be necessary to relocate new signs to avoid hiding or overwhelming historic ones, or to redesign proposed new signs so that the old ones may remain. (The legitimate advertising needs of current tenants, however, must be recognized.) Keeping the old sign is often a good marketing strategy. It can exploit the recognition value of the old name and play upon the public’s fondness for the old sign. The advertising value of an old sign can be immense. This is especially true when the sign is a community landmark.
  • Relocating the sign to the interior, such as in the lobby or above the bar in a restaurant. This option is less preferable than keeping the sign outside the building, but it does preserve the sign, and leaves open the possibility of putting it back in its historic location.
  • Modifying the sign for use with the new business. This may not be possible without destroying essential features, but in some cases it can be done by changing details only. In other respects, the sign may be perfectly serviceable as is.

If none of these options is possible, the sign could be donated to a local museum, preservation organization or other group.

Repairing Historic Sign Materials

Porcelain Enamel

Porcelain enamel is among the most durable of materials used in signs.8 Made of glass bonded onto metal (usually steel) at high temperatures, it keeps both its high gloss and its colors for decades. Since the surface of the sign is essentially glass, porcelain enamel is virtually maintenance free; dirt can be washed off with soap and water and other glass cleaners.

Porcelain enamel signs can be damaged by direct blows from stones and other sharp objects. If both the enamel surface and the undercoat are scratched, the metal surface can rust at the impact site. Because the bond between glass and metal is so strong, however, the rust does not “travel” behind the glass, and the rust is normally confined to localized areas. The sign edges can also rust if they were never enamelled. To treat the problem, clean the rust off carefully, and touchup the area with cold enamel (a type of epoxy used mostly in jewelry), or with enamel paints.

Dents in porcelain enamel signs should be left alone. Attempting to hammer them out risks further damage.

Goldleaf or Gilding

Goldleaf or gilding is both elegant and durable. These properties made it among the most popular sign materials in the nineteenth and early twentieth centuries. Surface-gilded signs (for example, gilded raised letters or symbols found on the exterior) typically last about 40 years. Damage to these signs occurs from weather and abrasion. Damage to gilded signs on glass normally occurs when the protective coating applied over the gilding is removed by harsh cleaning chemicals or scratched by scrub brushes. The sign can then flake upon subsequent cleanings.

Historic gilded signs can be repaired, typically by regilding damaged areas. An oil size is painted on the surface. The gold leaf is applied when the surface has become sufficiently “tacky.” Similarly, historic “reverse on glass” goldleaf signs can be repaired—by experts. A sample of the flaking sign is first taken to determine its composition. Reverse on glass signs use goldleaf ranging from 12 to 23 karats. The gold is alloyed with copper and silver in varying amounts for differences in color. (Surface gilding—on raised letters, picture frames and statehouse domes—uses 23 karat gold. Pure gold, 24 karat, is too soft to use in such applications.)

Metal letters E and R with neon tubes.
These tubes in this amusement park’s sign were broken and the surrounding “metal cans” needed work also. See below. Photo: Stan Fowler.

The damaged portions of the sign are then regilded in the same manner as they were done historically: the inside surface of the glass is coated with a gelatin; gold leaves about three inches square are then spread over the area. The new letter or design is then drawn in reverse on the new leaf, and coated with a backing paint (normally a chrome yellow). With the new design thus sealed, the rest of the leaf is removed. The sign is then sealed with a clear, water-resistant varnish.

Gilded signs, both surface and reverse on glass, can be cleaned gently with soap and water, using a soft cloth. Additionally, for glass signs, the varnish backing should be replaced every seven years at the latest.


Neon signs can last 50 years, although 20-25 years is more typical. When a neon sign fails, it is not because the gas has “failed,” but because the system surrounding it has broken down. The glass tubes have been broken, for example, thus letting the gas escape, or the electrodes or transformers have failed. If the tube is broken, a new one must be made by a highly skilled “glass bender.” After the hot glass tube has been shaped, it must undergo “purification” before being refilled with gas.

Workers repairing the metal letters in a large neon sign.
Workers prepare the “metal cans” from a sign for re-mounting. Photo: Larry Kanter.

The glass and the metal electrode at the end of the tube are heated in turns. As these elements become hot, surface impurities burn off into the tube. The resulting vapor is then removed through “evacuation”—the process of creating a vacuum. Only then is the “neon” gas (neon or mercury-argon) added. Neon gives red light, mercury-argon produces blue. Other colors are produced by using colored glass and any of dozens of phosphor coatings inside the tube. Green, for example, can be produced by using mercury-argon in yellow glass. Since color is so important in neon signs, it is vital to determine the original color or colors. A neon studio can accomplish this using a number of specialized techniques.

Workers installing new neon tubing in a large sign on a roof.
Neon fabricators are installing the new tubing in the repaired and remounted cans. Photo: Larry Kanter.


A failing transformer can cause the neon sign to flicker intensely, and may have to be replaced. Flickering neon can also indicate a problem with the gas pressure inside the tube. The gas may be at too high or too low a pressure. If so, the gas must be repumped.

Repairs to neon signs also include repairs to the surrounding components of the sign. The “metal cans” that often serve as backdrops to the tubing may need cleaning or, in case of rust, scraping and repainting.

As with gilded signs, repair of neon signs is not a matter for amateurs.

Summary and References

Historic signs once allowed buyers and sellers to communicate quickly, using images that were the medium of daily life. Surviving historic signs have not lost their ability to speak. But their message has changed. By communicating names, addresses, prices, products, images and other fragments of daily life, they also bring the past to life.

With halting steps I paced the streets, and passed the sign of “The Crossed Harpoons” —but it looked too expensive and jolly there. . . . Moving on, I at last came to a dim sort of light not far from the docks, and heard a forlorn creaking in the air; and looking up, saw a swinging sign over the door with a white painting upon it, faintly representing a tall straight jet of misty spray, and these words underneath — “The Spouter Inn: —Peter Coffin.”

The creaking wooden sign in Moby Dick identifies public lodging. But it also does a great deal more than that. It projects an image. It sets a mood and defines a place. The ability to convey commercial and symbolic messages is a property of all signs, not just those in novels.

Every sign hanging outside a door, standing on a roof, extending over a storefront, or marching across a wall transmits messages from the sign maker to the sign reader. Mixed in with names, addresses, business hours and products are images, personalities, values and beliefs.


  1. Bill Evans and Andrew Lawson, Shopfronts. New York: Van Nostrand Reinhold Co., 1981, p. 109, 114.
  2. Charles L.H. Wagner, The Story of Signs: An Outline History of the Sign Arts from Earliest Recorded Times to the Present “Atomic Age”. Boston: Arthur MacGibbon, 1954, p. 37.
  3. Rudi Stern, Let There Be Neon. New York: Harry N. Abrams, Inc. 1979, p. 19.
  4. Robert Venturi, Denise Scott Brown, and Steven Izenour, Learning from Las Vegas. Rev. ed. Cambridge, MA: MIT Press, 1977.
  5. George H. Kramer, “Preserving Historic Signs in the Commercial Landscape: The Impact of Regulation.” (Unpublished Masters Thesis: University of Oregon, 1989), p. 15. This section on sign regulation is heavily indebted to this work. See especially Chapter 2, History of Sign Regulation and Chapter 3, Mechanics of Sign Regulation, pp. 7-60.
  6. Berman v. Parker involved the condemnation of an older building for an urban renewal project. The decision “ironically would prove to be a major spur to a new wave of local preservation laws….” Christopher J. Duerksen, ed. A Handbook on Historic Preservation Law. Washington, D.C.: The Conservation Foundation and The National Center for Preservation Law, 1983, p. 7.
  7. A balanced approach to sign controls is offered by Peter H. Phillips, “Sign Controls for Historic Signs,” PAS Memo, November 1988. (Published by American Planning Association, Washington, D.C.).
  8. See John Tymoski, “Porcelain Enamel: The Sign Industry’s Most Durable Material,” Signs of the Times, December 1990, pp. 6671. For goldleaf, see October 1984 and November 1990 special issues of Signs of the Times. An excellent short “course” in neon evaluation is offered in Neon: The Good, the Bad, and the Ugly, by Paul R. Davis, Identity, Spring 1991, pp. 5659.


This publication has been prepared pursuant to the National Historic Preservation Act of 1966, as amended, which directs the Secretary of the Interior to develop and make available information concerning historic properties. Technical Preservation Services (TPS), Heritage Preservation Services Division, National Park Service prepares standards, guidelines, and other educational materials on responsible historic preservation treatments for a broad public.

This publication was originally written by Michael J. Auer (October 1991) and published on the US National Park Service.