The Trouble with Velcro TM - Is there an alternative?

Since the 1970s, large textiles have been hung using hook-and-loop fasteners, also known as Velcro TM,  which was an improvement for hanging textiles from rings, loops or tacks along the upper edge. Each of these methods created small areas of stress along the upper edge and often a 'scalloped' look. The technique has little changed from the first instructional handouts produced by the Textile Museum and the Smithsonian Institution. The looped side of the hook-and-loop fastener is machine stitched to a fabric, typically wide twill tape. The fabric is then hand-stitched to the reverse side of the upper edge of a textile; the hooked side is attached to the wall or cleat.

Over the years disadvantages of Velcro have come to light. Concern with its use began in the 1990s when discoloration of the product was noticed. Several conservators became concerned and were suspicious of product alterations resulting in color change and hook breakage, especially after the patent expired in 1978, resulting in various other brands of hook-and-loop fasteners coming on the market. Even so, Velcro and other hook-and-loop fasteners are still used today. However, it needs to be evaluated and possibly replaced every twenty years or so.

Old hook-side stitched to the outer edges of a quilt.

Velcro was invented in 1941 by George de Mestal, a Swiss engineer whose patent expired in 1978. With the patent's expiration the precise formulation of the previously known 'Velcro' could no longer be confirmed. Velcro of varying qualities and durability started to proliferate. Research by Kim Leath and Mary Brooks found that in 1998, two companies held the Velcro trademark despite producing notably different products. 

The Mag-Slat; An aluminum 'L'-shaped strip with fixed counter-sunk disc neodymium magnets.

An alternative hanging system is the Mag-Slat from SmallCorp, Inc.  A sleeve made of twill tape or Tyvek is made by machine-stitch to receive the steel powder-coated strip. To read more read this link.

Of course, more about the use of magnets can be found in Magnetic Mounting Systems for Museums and  Cultural Institutions, 2019. Get your copy now!  

Joy Gardiner and Joseph Webber. " Failure to Bind: A Re-examination of the Aging of Hook and Loop Fasteners." Textile Specialty Group Postprints. Vol. 20, 2010. pp. 155-120.

Kim Leath and Mary Brooks. "Velcro TM and Other Hook and Loop Fasteners: A Preliminary Study of their Stability and Ageing [sic] Characteristics." Textile Conservation Newsletter. Spring 1998 . pp. 5-11.

Magnetic Mounting Systems for Museums and Cultural Institutions Receives Major Review

Since the publication of Gwen's book, Magnetic Mounting Systems for Museums and Cultural Institutions, early last year, more than 350 copies have sold worldwide, including to 26 countries in addition to the US on 6 of the 7 continents. Among the purchasers are 145 museums and galleries, and 69 libraries. The book was also one of the recipients of the 2019 Awards for Excellence from the Greater Hudson Heritage Network.

2019 GHHN Award for Excellence
(Photo Credit: K.Sclafani, GHHN)

In 2019, Gwen spoke to six groups in the U.S., Canada, and Europe about magnetic systems, advocating for their use in a variety of applications.

Gwen presenting at an International Conference

In her review of Gwen's book, conservator Kloe Rumsey wrote in the December 2019 issue of News in Conservation,

"A book dedicated to the use of magnets for the mounting and display of museum objects has been eagerly awaited by the global conservation community for years....There has been significant buzz in the profession since we began to hear news of a book, and as we cross our collective fingers that it's as good as we want it to be, I'm happy to say that I think it is."

Rumsey calls out Gwen's attention to describing the scientific details of magnets, defining terms and theories within the body of the text for easy reference, illustrating the science and the systems with diagrams and figures, for drawing on case studies that offer "...tips, hacks and things to bear in mind when developing our own systems," and for providing useful tools for working with magnets.

The Triboelectric Series

Two- and Three-Part Magnetic Systems

As Rumsey concludes, "By producing this book, Gwen Spicer has introduced the wider community to these methods in accessible format, and we can now develop and grow in what we can achieve with it."

This isn't an instruction manual for a quick glance; it's worth spending time with this book to really be able to make creative decisions. While doing so might take longer than reading a set of instructions, we all know the benefits of working in this way for a varied collection. Some might say there's too much science, but this book provides all the information, and it's up to the readers to decide what they need to take away from it to achieve their own goals.

Order Magnetic Mounting Systems for Museums and Cultural Institutions

Magnetic Mounting Systems for Museums and Cultural Institutions for Sale at a Conference
(Photo Credit: K.Sclafani, GHHN)

Ms. Rumsey's review appeared in the December 2019 issue (75) of News in Conservation, the newsletter of the International Institute for Conservation of Historic and Artistic Works.

Overcoming the Challenges of Mounting a 39-foot Painted Textile

This year the Virginia Museum of Fine Arts asked Spicer Art Conservation, LLC to mount an unique painted textile from Tibet. The uniqueness of this artifact was not just due to the type of artifact, but also its dimensions. After all, how many artifacts do you know that are 39 feet long! The good news was that it was in a remarkable state of preservation for its monumental size.

The textile needed to be mounted for an exhibition, Awaken: A Tibetan Buddhist Journey Toward Enlightenment, that would later travel across the country to the Asian Art Museum in San Francisco.

The length is a critical part of the piece's iconography, which shows side-by-side deities. The deities, all with menacing appearances, are to be allies, not adversaries, facilitating the practitioner's spiritual progress. The painting is surrounded with rows of silk damask, as well as a pleated, double-layer ruffle along the bottom edge. This banner likely once hung on the walls of a monastery's main assembly hall or antis inner sanctum.

The painting layer out on the floor of a gallery for
examination (ca. 18th century, Tibet, opaque
watercolor on cloth).

Mounting this wonderful artifact had been a challenge for the museum. Using magnets was an appropriate solution, but what type of magnetic system would do the job? After all, due to the length the artifact would need to be rolled in at least one direction for the installation. Also the curator desired to have it installed where it would go around corners, allowing the viewer to 'enter' and be surrounded by it. I thought this was a really great, but really challenging idea. Just mounting it on 39 feet of straight wall would be challenging!

The obvious mounting system was to use the magnetic slat, fabricated by SmallCorp, Inc. But what gauge of steel could be rolled while also being thick enough to maintain the pull force of the magnets? The powder-coated steel with the magnetic slat is a gauge-24 (0.0276" / 0.7010 cm). This was too stiff and the coating was not flexible enough to withstand several rollings.

After much searching and investigating, a local manufacturer was found who makes steel air ducts. They had the ability to cut a continuous strip of galvanized steel, 1-inch wide in a gauge-26 (0.0217" / 0.5512 cm). We found that it could easily roll over an 18-inch diameter tube. The small jump between gauges 24 to 26 is not much, however, the thinner gauge was just enough to allow for the needed curvature, while also being able to return to a straight and flat surface.

From the start, it was clear that the painted textile needed to be rolled onto two large diameter tubes. The installation would begin at the center of the mount installed on the wall, working each side out, one at a time. This would insure its center and positioning. Unlike paper that is often rolled on a tube for installation, due to its stiffness, textiles -- even painted ones -- require support from the upper edge. Another issue to solve. In order to support the textile and provide a sleeve for the galvanized steel, Tyvek was used. The sleeve was sewn into the top edge of the Tyvek to hold the steel. The Tyvek was also kept long to act as a barrier for the painted regions during the rolling process. This was then attached to the reverse side of the banner providing support, protection and housing the steel needed for the magnetic system.

Preparing the Tyvek sleeve and backing for the scroll.

Painting conservator, Nancy Pollak inpainting
 on-site at Spicer Art Conservation's studio

Gallery before installation.

Last stages of installation.

With the help of the team at Spicer Art Conservation, LLC, and along with the mount makers and the art handlers at the VMFA, the scroll was successfully installed for the exhibition.

Learn more about magnets and their many uses in the new publications Magnetic Mounting Systems for Museums and Cultural Institutions. Available for purchase at www.spicerart.com/magnetbook.

Magnetic Mounting Systems for Museums and Cultural Institutions is now available!

The book is now available and it is time to get yours today! 

We have been waiting for this day for a long time. I especially want to thank all of those who pre-ordered books. In all, they ordered over eighty books. Some ordered at the time of the International Mountmaking Forum in London. Since that meeting, there has been a steady flow of orders from museum professionals, framers and mountmakers globally. I have been overwhelmed and pleased by this early support and enthusiasm for the book.

All the boxes delivered. 

The book! It looks really great, too.

How do I get a book? It is easy, you can go here to place your order and we will ship a copy to you.  Are you going to be at this years AIC annual meeting in Connecticut and don't want to wait or pay for shipping? It is only a few weeks away. I will be there too selling copies of the book.

How do you find me at AIC? You can find cards with ordering information at SmallCorp's table in the exhibit hall. Or look for conservators wearing a large button with the book cover. These conservators will also have cards with ordering information available. Or you can just find me walking around. I will have books available for purchase and am happy to arrange meeting up with people to facilitate the purchases; just send me an email at gwen@spicerart.com and we can work out the details!

An assembly line was needed for
the packaging of all of the books.

These books are headed abroad!

All of the pre-ordered books packaged and ready
to be shipped out!

Magnets to the Rescue for Mounting Paper, Books and Label Text

I have recently been contacted by a conservator at the Winterthur Museum regarding the display of books and archival materials using magnets. As part of the conversation, we discussed the idea of converting the existing display case where small pins and tacks are used to support artifacts into a full magnetic system.

It turns out that a magnetic system is perfectly suited for use with these types of materials. This is especially the case when using a three-part magnetic system. Such a system would use one magnet between two layers of ferromagnetic materials, ie steel. One layer of steel is the actual back wall of the case with the second steel part being the armature as seen in the image below. The use of a three-part system almost doubles the strength of the single magnet, allowing for the support of even heavier artifacts when using the stronger neodymium type of permanent magnet. An example of a two-part system can be found in an earlier post on the mounting of leather gloves.

The variations of two-part and three-part magnetic systems, a) Magnet-to-magnet; b) Magnet-to-ferromagnetic
material; c) Ferromagnetic material-to-magnet-to-ferromagnetic material.

A range of armature shapes and sizes made of either steel or another ferromagnetic material can be created independent of the magnet. Separating the parts allows for each to be stored. Remember the importance of proper storage of magnets.

I recently visited the musée de quai branly, in Paris. The conservator, Eleanore Kissel, generously gave me a tour of the galleries and conservation studios. Below are some images from the visit. The quai branly is unique in that their gallery display cases, designed in 2006, were purposely designed to use magnets. They are perhaps the first museum to so fully embrace a wide use of magnets. Since that time, magnetic systems have become more sophisticated and fine-tuned. It was wonderful for me to see all of the creative solutions each using magnetic force!

Having an entire surface of steel means that artifacts can be placed anywhere on the panel with no marking of the surface. This eliminates the need for filling holes in the wall between each gallery rotation. Steel, with a durable powder-coat, can also be placed in a gallery's deck and ceiling.

The armature for this basket is
attached to the cup with a magnet inside.

Magnets in 'cups' or 'pots' produce a strong pull force. The cups are available with counter-sunk holes for securing into wood or other materials or into a protruding flange as seen in images above. All of these armature elements can easily be moved and readjusted to accommodate fine-tuning.

The 'J'-shaped armature is attached to the back wall with a magnet. A
decorative coat-layer was added to the face of the steel. The armature
elements are discretely placed, to support both the lower and upper edges
of the matted works of art.

A modular system for labels can also be created with flexible magnets behind them. The printed text can then be inserted into an appropriately sized sleeve. A range of products are available for such things and the internet is filled with a variety of ideas demonstrating the range of aesthetic options and prices.

I hope that I have shown the great flexibility that using a magnetic system can offer in displaying a wide variety of artifact types, all without the visitor knowing. 

Learn more about magnets and their many uses in the new publications Magnetic Mounting Systems for Museums and Cultural Institutions. Available for purchase at www.spicerart.com/magnetbook.

What are Flexible Magnets?

You know them and we bet you even own a few! We're talking about flexible magnets, also sometimes called refrigerator magnets, which first appeared as a type of ceramic magnet in the 1960's. 

Because they're made with flexible resins and binders (synthetic or natural rubber) this type of magnet can be produced as 1) extruded magnetic profiles that are usually coiled or 2) in sheets, resulting in a wide variety of options and properties. For example, extruded flexible magnets are often found on shower door or refrigerator closures. Magnetic sheets, on the other hand, can be cut into all sorts of shapes and sizes, and are what you find holding that souvenir of your summer vacation to your refrigerator door or office filing cabinet.

When flexible magnets are extruded, they pass through a line of powerful cylindrical permanent magnets or a rotating magnetic field. This step allows for the creation of a wide variety of options. For instance, they can be formed to have holding power on both sides, or only on one side. 

The most commonly arranged magnetic poles occur in an alternating line format on the same surface plane (NSNSN or SNSNS). An interesting phenomenon occurs when two layers are slipped slightly on top of one another: they both repel and attract as one slides across the surface of the other. One side of the flat surface is more magnetic (has an increase in holding force) than the other. This arrangement of polar direction is called the Halbach Array. It is this alternating polarity that creates modest attraction (fig. 1). 

Figure 1: A cross-section of a Halbach array with the alternating poles that create a stronger magnetic
field on one side and a weaker one on the other.

The most common style used in museums is the multi-pole on one side. In museums, flexible magnets are commonly used to attach accession or object numbers in documentation photography, for overall humidification as a substitute for weights, holding wrapper enclosures closed, and mounting of lightweight flat artifacts. Their continuous magnetic field is ideal for overall support; their low pull force, however, does not allow them to support heavy or thick items (Schlefer, 1986; Stenstrom, 1994; Braun, 2001; Keynan et al., 2007; Vilankulu, 2008; Heer et al., 2012; Migdail, 2013).

The pull force of flexible magnets is quite weak, and they have low magnetic strength when compared to a non-bonded magnet. Today, the flexible-style magnet is also formed with neodymium (further described in the following section), creating a much greater pull force. Thickness of the flexible material is in direct relation to the pull force of the magnet. Manufacturers specify pull force in pounds per square foot. Pull force is related to thickness; the thicker the sheet, the stronger the magnet. A flexible magnet .04 cm (.015 inches) thick has a pull force of roughly 40 pounds per square foot (0.278 PSI) while a flexible magnet .08 cm (.030 inches) thick has a pull force of roughly 85 pounds per square foot (0.59 PSI). No other magnet type has such clear-cut specifications; therefore comparing flexible magnets with others is not easily transferable (table below).

Table: Thickness of the flexible magnet and the pounds per square inch of pull force

Thickness	Approximate pounds per sq. ft.	Pounds per square inch (PSI)
.012	30	0.2
.015	40	0.278
.020	60	0.417
.030	85	0.59
.060	144	1

Flexible magnets are very susceptible to demagnetization, especially when in contact with other stronger magnets and with other similar flexible magnets (fig. 2) (Livingston, 1996). They also appear to lose their magnetization over time, likely due to proximity to other magnets. Flexible magnets are less susceptible to demagnetization by their Curie Temperature. When used in a situation where strength is needed, they should be checked occasionally.

Figure 2: The parallel rows of the flexible magnet visible with a
'magnetic viewing film (left). The same parallel rows disrupted
when exposed to a rare-earth magnet (right).

Flexible, bonded type magnets are conducive to creating large area pressure type systems. These ferrite-bonded magnets are weak, but to increase the strength, the polar directions are arranged as in a Halbach Array during manufacture. It is this alternating polar direction that provides gentle pressure, evenly dispersed over an entire surface. Conservators use the standard magnetic orientation of a magnetic force on one side. Sheets can vary in alignment when placed together and should be trimmed as a pair. Their strength can be increased somewhat by using both thicker flexible magnets and a related gauge of metal (Spicer, 2014). A second layer of flexible magnet placed on top does not add to the pull force of the first layer, due to its particular alternating polarity.

The addition of pressure created by the pull force can both introduce and assist in the removal of moisture during humidification of an artifact. An artifact sandwiched between absorbent materials is given overall pressure either between two flexible magnets or a top flexible magnet layer above and a steel plate below. The presence of the sandwiching method has been noted to slow drying time (Blaser and Peckham, 2006), but the benefit of not having to lift heavy weights offsets this.

Learn more about magnets and their many uses in the new publications Magnetic Mounting Systems for Museums and Cultural Institutions. Available for purchase at www.spicerart.com/magnetbook.

Resources

As a conservation tool, flexible magnets have been successfully used for a wide range of applications, including during humidification of paper and book repair as a substitute for weights (Brooks, 1984; Stenstrom, 1994; and Blaser and Peckham, 2006); an embellishment attachment with two layers of flexible sheets (Braun 2001); and mounting (Keynan et. al., 2007; Heer et al., 2012; and Migdail, 2012).