In acoustics, the energy of sound waves entering any material rather than being reflected.

Materials that absorb sound energy. Typically only those materials that have been tested and assigned sound absorption coefficients (see NRC).

A non-profit organization that establishes standard tests and specifications. Now known as just ASTM.

American Society for Testing and Materials

The test method for determining the surface burning characteristics of building materials. This test is applicable to exposed surfaces such as walls and ceilings. This test method is sometimes referred to as the “Steiner tunnel test”. This test method is for single products, not assemblies. The test evaluates both flame spread and smoke development and assigns different classes based upon test results.


For tackable and acoustical panels, an additional piece of fabric placed behind a fabric covering to provide opacity or for purposes of design. This is typically a sheer, loosely woven cotton or linen fabric used expressly for this purpose and referred to as “scrim”.

A material applied to the back of a fabric to provide a surface for applying an adhesive or to stabilize a fabric. Back coatings prevent adhesive “strike-through”; the migration of applied adhesive from the back of the fabric through to the front. Strike-through can occur immediately after application or over time. Back coatings (sometimes erroneously referred to as “backing”) are typically made from latex or acrylic.

Note Back coating is most often used to stabilize lesser quality fabrics in order to enhance their wear characteristics. It is interesting to note that this practice occurs principally in the United States. Most back coatings are not VOC free and they will render a recyclable fabric, non-recyclable. When adding a back coating to a fabric you are reducing the material’s acoustical transparency. It should also be noted that most back coatings will break down over time and absorb moisture.

A technique employed to retain the advantages (ease of installation and in-place fabric replacement) of front loading panel track while covering the track’s side with a matching or contrasting fabric.

For tackable and acoustical panels, the panel is considered to have a beveled edge profile when the face of the panel turns up at the edge at approximately 45º for, depending upon panel thickness, 3/8” to 5/8” around the perimeter of the panel.

A CFA (cutting for approval) is a small snippet of fabric taken from the bolt that has been reserved for your order. This piece serves as a confirmation of pattern and color. Once you have approved the CFA, your fabric will be shipped. Due to improved dye lot consistency, many manufacturers have discontinued the practice.

COM (customer’s own material) is a term used when you bring your own fabric into the project instead of using the manufacturer’s selection of textiles for that item.

Refers to fabric remaining after cutting along the fabric’s length. Unusable cut-off should be avoided. See “Fabric Utilization”.

This refers to the particular batch or run of an item. Often there are color changes from batch to batch; therefore it’s important to order a CFA. Dye lot changes are to be expected though modern technology has minimized variances.

For tackable and acoustical panels, the shape of the outside (visible) edge of the panel. Typical profiles are square, beveled, and radius.

All fabrics will fade over time with prolonged exposure to direct sunlight. The issue is how much, and how fast. Most fabric manufacturers submit their fabric to certified laboratories for independent testing. Again, most test to the American Association of Textile Chemists and Colorists (AATCC) standards. A summary of the test method is as follows.>


AATCC 16 Option 1 or 3 – 2003*

The AATCC 16 Option 1 and 3 are test methods of the American Association of Textile Chemists and Colorists (AATCC). ACT recognizes both methods where the only difference is the light source being used. In AATCC 16 Option 1 a Carbon-Arc lamp is used as the light source and in AATCC 16 Option 3 a Xenon-Arc lamp is used. Under both methods a strip of fabric (part of which is protected by a special paper card) is placed in a fadometer and exposed to 40 hours of accelerated fading units (AFU). After the exposure the difference in color between the exposed and protected parts of the fabric are compared to the AATCC gray scale and the degree of fading is rated.

Grade 5
no fading

Grade 4
slight fading

Grade 1
high degree of fading

Note: One of the unique features of the Fabricmate pre-made panels is that the fabric cover is not glued to the surface of the panel. Instead it is held in the jaws of our panel frame. Should fabric replacement ever be necessary, there is no need to purchase a new panel, just remove the old fabric and install a new piece.

Optimization of fabric use through fabric selection (primarily usable width) and layout. Optimizing the usable width of the fabric is sometimes referred to as “splitting the width”.

A wood-composite substrate used in the construction of acoustical and tackable panels.

For tackable and acoustical panels. Fiberglass is a semi-rigid acoustical material (sometimes referred to as fiberglass “batting” or “batts”) comprised of glass fibers bonded with a thermosetting resin. They are available in various thicknesses and densities with varying NRCs. Traditional “yellow” products contain formaldehyde, a known volatile organic compound (VOC). Lately, “white” VOC free versions have become available.


While these new “white” versions are VOC free, when used in the manufacture of “wrapped” panels the edges of the fiberglass are first “dipped” in a hardening resin to add modest durability and the fabric is glued to the face of the fiberglass. Often, both the resin and the adhesive contain VOCs, negating any product benefit. “White” fiberglass is not constructed from recycled materials although this is often erroneously inferred.

For tackable and acoustical panels. Typically a panel comprised of fiberglass batting that has its edges hardened with resin and fabric glued to the face and sides.

A numerical designation, applied to a building material, which is a comparative measure of the ability of the material to resist flaming combustion over its surface. The rate of flame travel, as measured under the applicable ASTM E 84 test, in which a selected species of untreated lumber has a designated value of 100, and noncombustible inorganic reinforced cement board has a value of 0.

A single number measurement of the flame spread across the surface of a material. Defined by ASTM E 84 commonly known as the 25-foot tunnel test, the number is obtained by comparing with red oak flooring.

For Fabricmate Pre-made Panels and Modular Panels System, the “frame” performs several functions. It provides protection for edges of the panels, defines the edge profile, and incorporates a “hidden” fabric channel and the fabric retention jaws and establishes the foundation for the panel’s “floating-fabric” design.

Wire employed to suspend baffles, clouds, or diffusers from an existing structure. Hanger wires and related components should be load rated for the materials they will be supporting.

For tackable and acoustical panels, the arrangement of panels or panel systems such that seams or butt joints extend horizontally across the surface to be covered.

Horizontal Layouts are, in most cases, more attractive, present more design opportunities, and typically result in greater material utilization (principally fabric) and decreased installation costs.

An arrangement or a plan, especially the schematic arrangement of parts or areas: the layout of a building; the layout of wall finishes, etc. See “Horizontal Layout”, “Panelized Layout”, and “Vertical Layout”.

The Leadership in Energy and Environmental Design, Green Building Rating System, developed by the U.S. Green Building Council (USGBC), provides a suite of standards for environmentally sustainable construction.

A proprietary product of Fabricmate Systems, Inc. A veneer available on Pre-made panels, Modular Panel Systems, and Site-fabricated Panel Systems that creates a surface that is both tackable and magnetically receptive.

Mag-Tack® veneer is not acoustically transparent and has not been tested to meet the requirements of ASTM E 84, Class A. Mag-Tack® is intended for use with Neodymium (“rare earth”) magnets. Other types of magnets may not be fully compatible.

A piece of fabric, carpet or other material, usually between 8” and 10” square, that is representative of the product. The sample generally comes with a paper “memo” attached that contains pertinent technical information.

A high density vinyl material that acts as a barrier to sound transmission. Typically directly applied to surfaces or suspended. See Sound Transmission Class.

A non-rigid acoustical substrate (also known as “rock wool” or “slag wool”) made from molten rock.

A single-number rating system used to compare the sound-absorbing characteristics of building materials. It rates the ability of a wall panel, ceiling panel, or other construction material to absorb sound. NRC is the fraction of sound energy, averaged over all angles of direction and from low to high sound frequencies that is absorbed and not reflected.

NRC is the average of sound absorption readings measured at four frequencies: 250, 500, 1,000 and 2,000 Hz, and expressed as a number between 0 (perfectly reflective) and 1 (perfectly absorptive) to the nearest integral multiple of 0.05. Materials claiming an NRC of greater than 1 (when 1 is perfectly absorptive) are the result of an arithmetical calculation and may be misleading.

There is no direct relationship between the NRC of a particular material and the amount of total sound absorption that will occur in a given space. The size and shape of the space, the construction materials used, the type and number of space openings, the contents of the space, the amount of intended surface coverage, and the frequencies of the sound that will occur in the space are all factors. Using a material with a higher NRC will not necessarily result in a discernible increase in sound absorption.

An office (typically a larger room) in which screens or panels, typically 60” high, are used in lieu of ceiling-high partitions.

For tackable or acoustical panels, a flat board of any material and in any size, or multiple boards used as part of a system, that are mounted to a vertical or horizontal surface.

A layout is said to be “panelized” when there are many vertical, or both vertical and horizontal seams. This results from the intentional use of many individual panels that are either “butted” or “tiled” together, or by the use of intermediate joints in a site-fabricated panel system. A layout with many of these seams is often described as “highly panelized”.

A dividing wall within a building; may be load-bearing or non load-bearing. In sound transmission considerations, any building component (or a combination of components), such as wall, door, window, roof or floor-ceiling assembly, that separates one space from another.

For tackable and acoustical panels, the panel is considered to have a radius edge profile when the face of the panel turns up at the edge the fixed radius of a circle at approximately 90º for, depending upon panel thickness, 1/4” to 1” around the perimeter of the panel.

A proprietary product of Fabricmate Systems, Inc. ReCore® is a high-impact, 100% polyester material with a 65% post consumer content (recycled plastic beverage containers). ReCore® can be used alone or in conjunction with fabric and other materials to produce aesthetic, acoustical, and tackable panels and panel systems. Refer to “substrate”.

Persistence of reflected sound in a room after its source has stopped emitting sound. When sound is produced in a space, a large number of echoes build up and then slowly decay as the sound is absorbed by the walls and air, creating reverberation, or reverb. This is most noticeable when the sound source stops but the reflections continue, decreasing in amplitude, until they can no longer be heard. Large chambers, especially such as congregation halls, theaters, gymnasiums, indoor swimming pools, etc., are examples of spaces where the reverberation time is long and can clearly be heard.

Time required for a sound to drop 60 decibels. Rooms for speech require a shorter reverberation time than for music as a longer reverberation time can make it difficult to understand speech. If the reverberation time from one syllable overlaps the next syllable, it may make it difficult to identify the word. “Day”, “Date”, and “Daze” may all sound very similar. This subject of being able to hear speech clearly is referred to as “speech intelligibility”.

A sheer, loosely woven cotton or linen fabric used as “backing”.

The ratio of smoke emitted by a burning material to the smoke emitted by the red oak standard (ASTM E 84).

A relative numerical classification of a building material as determined by an ASTM E 84 test of a material’s surface burning characteristics.

A single-number rating system used to rate the effectiveness of a wall, partition, door, or window in blocking sound. The STC number is derived from sound attenuation values tested at sixteen standard frequencies from 125 Hz to 4000 Hz. These transmission-loss values are then plotted on a sound pressure level graph and the resulting curve is compared to a standard reference contour.


The STC ratings are heavily weighted toward frequencies above 125Hz which correlates to human speech and hearing acuity. It is of substantially less value with respect to machinery, HVAC, sub-woofers, and other low frequency noise generators. Most STC ratings are a result of laboratory testing and must be discounted, sometimes to very great extents, in field environments where actual conditions do not mimic laboratory conditions. Additionally, STC testing procedures have changed over time and materials with test dates prior to 1999 may have to be discounted. STC values are not additive (i.e. two pieces of material with an STC of 20 do not result in an STC of 40).

Typical Partition Types and Sound Transmission Examples

STC Partition Type

33 Single layer of 1/2” drywall on each side, wood studs, no insulation (typical interior wall).
45 Double layer of 1/2” drywall on each side, wood studs, batt insulation in wall (typical exterior wall).
46 Single layer of 1/2” drywall, glued to 6” lightweight concrete block wall, painted both sides.
54 Single layer of 1/2” drywall, glued to 8” dense concrete block wall, painted both sides.
55 Double layer of 1/2” drywall on each side, on staggered wood stud wall, batt insulation in wall.
59 Double layer of 1/2” drywall on each side, on wood stud wall, resilient channels on one side, batt insulation.
63 >Double layer of 1/2” drywall on each side, on double wood/metal stud walls (spaced 1” apart), double batt insulation
72 8” concrete block wall, painted, with 1/2” drywall on independent steel stud walls, each side, insulation in cavities.


STC Sound Transmission Examples

25 Normal speech can be easily understood.
30 Loud speech can be understood fairly well, normal speech can be heard by not understood.
35 Loud speech can be heard but not understood.
42 Loud speech audible as a murmur.
45 Loud speech not audible.
50 Very loud sounds such as musical instruments (higher frequencies) can be heard but lack clarity.
60 Very loud sounds such as musical instruments (higher frequencies) can be faintly heard.
75 Most airborne noises blocked.

STC partition ratings taken from: “Noise Control in Buildings: A Practical Guide for Architects and Engineers”; Cyril M. Harris, 1994.

The intelligibility of speech (usually measured in the presence of noise or distortion). The quality of language that is comprehensible

For tackable and acoustical panels, the panel is considered to have a square edge profile when the face of the panel turns up at the edge at approximately 90º around the perimeter of the panel.

For tackable and acoustical panels, the underlying material to which a covering is applied, or by which it is supported. A substrate (sometimes referred to as “core”) can also have important functional characteristics such as acoustical performance, impact resistance, and tackability.

Any metal member of the “T” cross section used in ceiling suspension systems.

For substrates, a material that will accept and hold a tack, push-pin or similar device and that may be used repeatedly for that purpose. For fabrics, a material that will accept use of a tack, push-pin or similar device without showing the result of that use.

The principal component of the Fabricmate Systems Site-fabricated System. The track incorporates a “hidden” fabric channel and the fabric retention jaws. The “track” defines the area to be panelized and establishes both perimeter and intermediate fabric insertion points. It is the foundation for the “floating-fabric” design.

A systematic method to improve the “value” of goods and services by using an examination of function. Value, as defined, is the ratio of function to cost. Value can therefore be increased by either improving the function or reducing the cost. It is a primary tenet of Value Engineering that quality not be reduced as a consequence of pursuing value improvements.

For tackable and acoustical panels, the arrangement of panels or panel systems such that seams or butt joints extend vertically from floor to ceiling.

Vertical Layouts are, in most cases, less attractive and typically result in greater material waste (principally fabric) and increased installation costs.