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18 11, 2015

Environmental Factors and Fabrics

By |November 18th, 2015|Education, Fabrics, Flame Retardancy|2 Comments

Summer seems to have finally ended here in sunny SoCal – and now out come the sweaters and the scarves.  Which brings me to thinking about the environmental effects that seasonal changes have on many of the fabrics that we cut and sew (and sell) right here at Sew What? Inc.


Generally speaking, the trend over the last few years has been to shift over to polyester textiles, especially Avora and Trevira polyesters – mostly for their extreme durability in terms of being flame resistant – often times for the life of the fabric. Because flame retardancy is added during the manufacture of the fibers themselves (rather than through a topical treatment of the fabrics), the fibers (and the resulting fabrics) are considered inherently and permanently flame retardant. The flame retardancy will not be removed through washing or dry-cleaning.  Needless to say, these technological changes in fiber content and the resulting fabrics has been industry changing for the entertainment softgoods market.

But there is yet another benefit to staying within the polyester based fabric lines – and that is their resistance to climate changes.  Unlike a cotton or a cotton mix – you won’t get shrinking with moisture.  Traditional cotton velour will shrink as much as an inch and a half every 10 feet (which can be significant on a 40 foot high drape).  Cottons are topically treated with chemicals to ensure their flame resistance – and did you know that those chemicals will “frost” if exposed to high moisture?  You have likely seen some old school drapes that has what look like water marks on them.  That’s where the chemical treatment has been exposed to water or high moister and the chemical has effervesced.

Polyester velours, such as Encore Velour – offer the buyer both flame resistance and weather resistance.  NOT that I am suggesting you hang them out in the rain.  That would not be wise as they are not UV resistant!  But the fact that you can have poly drapes in a venue where there are heavy shifts in moisture or temperature – (such as when water cooled air conditioners are employed) or if you have dehumidifiers in use just “some” of the time.

I also like the polyesters, such as poly muslin, for their color fastness.  We have in rentals some drapes that have been well washed – and have worked hard – and the color is still good and solid. For black drapes where you don’t want a “fade to grey” the poly based products again win hands down.

I’m a fan of 100% cotton for specific uses – the cotton velours are more gorgeous and the absence of any man-made fiber means that they aren’t reflective.  This can be a lighting designers dream!  Love to see traditional cottons used in traditional theatrical environments – with both controlled climates and controlled lighting conditions.


The 100% poly products bring it home for venues and locations that are high traffic – high wear – and even high humidity.  Gymnasium retrofits, cafeterias, touring productions going into a variety of venues, house of worship environments with lots of drapery changeovers.  And of course concerts – rock and roll means the drapes work hard.  The polyester textiles will do so much better in the long run.  More durable and more likely to successfully pass flame testing and a variety of venues over an extended period of time.

10 09, 2015

The Basics of Fabric Flammability and Flame Retardancy

By |September 10th, 2015|Education, Flame Retardancy|3 Comments

So, you have recently heard about flame retardancy (perhaps from a fire marshal who asked you if you have a flame certificate showing that your digital backdrop is flame retardant, or you were told that the new custom stage curtains that you plan to purchase need to be flame retardant), but you don’t have a clue what that means.  No need to worry – this blog post contains the information you need to become familiar with this complex subject.

SS_Lady Gaga 2

Fabric Flammability

Fabric flammability is an important issue to consider, especially for drapery that will be used in a public space such as a school, theatre or special event venue, since government regulations require that drapery fabrics used in such spaces be certified as fire retardant. Although all fabric will burn, some are naturally more resistant to fire than others. Those that are more flammable can have their fire resistance drastically improved by treatment with flame retardant chemicals.

Certain synthetic fibers are extremely flame resistant, including glass fibers and modacrylic. Other synthetics, including certain polyesters, are slow to ignite and may even self-extinguish. However, once synthetic fabrics ignite, they will melt rather than flame. The resulting substance can lead to severe burns if it comes into contact with the skin.

Natural fibers typically do not melt. Wool and silk burn slowly, are difficult to ignite, and may self-extinguish. With other untreated natural fabrics, such as cotton and linen, the fabric can ignite quickly, resulting in a fast moving flame spread. Fabrics that include a combination of natural and synthetic fibers, such as polyester-cotton blends, can be particularly troublesome, as they combine the fast ignition and flame spread of the natural fiber with the melting aspect of the synthetic fiber.

The ignition and burn factors of fabric are also affected by the weight and weave of the fabric. Lightweight, loose weave fabrics will burn more quickly than heavier fabrics with a tight weave. In addition, fabric flammability can also be affected by the fabric’s surface texture, with napped fabrics (such as velvets and velours) igniting more easily than fabrics with a smooth surface.

Fire Retardancy of Fabrics

The good news is that the flammability of fabric can often be drastically reduced through the use of fire retardants. Many natural fibers, including cotton, can be topically treated with a chemical that reduces the fabric’s flammability to the extent that it becomes nearly non-combustible. During a fire, the chemical reacts with the gases and tars generated naturally by the fabric, converting the gases and tars to carbon char, thus drastically slowing the fabric’s burning rate.

Some polyester fabrics are considered permanently flame retardant. This is because the fabrics are manufactured utilizing fibers for which the flame retardant properties are built directly into the molecular structure of the fibers. Fabrics manufactured utilizing Trevira™ and Avora™ polyester fibers are considered inherently or permanently fire retardant. Other synthetic fabrics may be considered durably fire retardant, fire retardant, or non-fire retardant. “Durably fire retardant” refers to a process in which polyesters are chemically treated during the manufacturing process with a non-water soluble chemical. In other cases, synthetic fabrics may be topically treated with chemicals after the manufacturing process (in the same manner as natural fibers such as cotton), or may be untreated (or untreatable) and therefore considered non-flame retardant.

When a fabric is designated as “inherently flame retardant,” “permanently flame retardant,” or “durably flame retardant,” the flame retardancy will typically last for the life of the fabric, as long as the fabric is properly maintained. The drapery can be laundered or dry-cleaned as recommended by the drapery manufacturer. In the case of fabrics that are designated as “flame retardant,” that have been topically treated with chemicals, the flame retardancy of the fabric will dissipate over time, particularly with repeated cleaning. These fabrics must be dry-cleaned with a non-liquid cleaning agent. Typically, the flame retardancy of topically treated fabric is certified for one year, though the actual length of time in which the treatment remains effective will vary based on the number of times the drapery is dry-cleaned and the environmental conditions of the location in which the drapery is used. It is recommended that drapery be re-tested for flame retardancy on an annual basis, and topically treated by a qualified professional as needed. 

Flame Retardancy Regulations

In the United States, there is no federal law regarding fabric flammability.  Instead, most states have instituted laws requiring that fabric used as hanging drapery in public spaces must meet NFPA 701 and/or NFPA 705 standards, created by an industry group, the National Fire Protection Association.  To meet these standards, fabrics are laboratory tested (NFPA 701) or field tested (NFPA 705). There are a number of factors involved in these tests, but essentially samples of the fabrics are set on fire and must self-extinguish within a certain amount of time.

Although most states and cities require that drapery (and other hanging fabrics) are certified to meet NFPA 701 / NFPA 705, there are a few exceptions. California law requires that fabrics meet a different standard, Title 19, with a similar (though not identical) testing method, and that fabrics, flame retardancy chemicals, and flame retardancy applicators / testers be registered with the Office of the State Fire Marshal. Though New York City regulations are based on NFPA 701 standards, that city has its own specific requirements, as does Boston.

Internationally, flame retardancy regulations vary widely.  In Europe alone, there are different regulations in the UK, Germany, and France, just to name a few. Australia has its own regulations as well.  There is no international standard for fabric flame retardancy.

Certification of Flame Retardancy


When purchasing custom stage curtains or flame retardant fabric, always request a Certificate of Flame Retardancy from the drapery or fabric supplier.  This certificate (commonly referred to as a Flame Certificate) certifies that the fabric (as a sewn drape or as raw fabric) meets specific flame retardancy standards.  In the United States, this usually means that the fabric meets NFPA 701 standards.  Some (but not all) suppliers can also certify for California standards and/or New York City requirements. Occasionally, a supplier can certify a fabric for another country (such as the UK or Germany), but this is the exception rather than the norm.

A Certificate of Flame Retardancy is typically valid for one year, after which it is recommended that the fabric or curtains be re-tested for flame retardancy.  This is because a variety of conditions can affect the flame retardancy of fabric (even fabric that has been certified as inherently flame retardant).  Depending on the fabric and the type of flame retardancy (FR, DFR, PFR, or IFR), a fabric’s flame retardancy can be affected by a number of factors, including laundering, repeated dry cleaning, dust accumulation, use of pyrotechnic chemicals near the drape, and more. Therefore, it is prudent (and some fire marshals require) to have the drapery tested and re-certified periodically by a certified flame retardancy applicator / tester, and to retreat or replace any drapery that does not pass periodic retesting.

11 08, 2015

Taking Your Custom Stage Curtains Overseas? Consider Flame Retardancy Requirements

By |August 11th, 2015|Education, Fabrics, Flame Retardancy|2 Comments

Since many of our customers are in the music touring industry, it is not unusual that they use our custom stage curtains or our rental LED backdrops in venues not only throughout the United States but throughout the world. One thing that needs to be considered is that there is no international standard regarding flame retardancy of stage drapery.


If you buy stage drapery – whether it is a custom band backdrop or an Austrian curtain or a masking drape – and plan to use it in multiple countries, it is important to become educated on flame retardancy requirements in the countries you will visit.  For example, a Certificate of Flame Retardancy to NPPA 701 (the U.S. national standard)  will not be accepted in Germany or the United Kingdom, just as certification to Germany’s B1 standard or the UK’s 5867-2 standard would not be accepted in the United States.

Because there are so many different standards throughout the world, it is rare for a fabric mill or drapery supplier to provide flame retardancy certification for any countries other than their own.  There are a exceptions (for example, here at Sew What?, we are able to provide UK and/or German certificates and lab test results for a few of our most common touring fabrics), but generally, certification is provided only for the standards of the country in which the fabric mill or drapery supplier is located.

That doesn’t mean you have to buy new drapery in every country you visit! It just means that you need to be prepared.  Talk to venue managers or promoters in each country.  Find out what the process is to get your drapery approved for use (in advance if possible).  You may be able to have a small burn sample tested on site, or you may need to send a sample in advance for approval. Whatever the case, it is always better to know in advance what the steps are so that you aren’t surprised the day of the show!

Want to learn more?  Check out our pdf document “Flame Retardancy Regulations Throughout the World.”

20 07, 2015

To Re-Purpose or Not? When Doing Good Becomes Hazardous

By |July 20th, 2015|Education, Fabrics, Flame Retardancy, Projects|2 Comments

Here is an EXCELLENT question that was just submitted to us with regards to re-purposing old stage backdrops:

“Hi, Sew What? team! Wanted to see what kind of fire retardant are sprayed on the old  band backdrops?  We have a bunch from old tours, and were thinking we would cut them up and make tote bags out of them. However, we realized that if they are sprayed with toxic chemicals that would not be good idea…… Could you send what kind of retardant was used and if it’s safe for us to repurpose this material into totes that we can sell to fans?”

Ken Ches_29

Here was our response and suggestions:

All fabrics are handled differently when it comes to flameproofing. If you have old backdrops, and don’t know what the cloth is or when they were purchased, you will have some difficulty in identifying whether or not they are potentially hazardous for use in a product targeting individual end users in the retail marketplace.

An IFR fabric backdrop would most likely not have any chemical on it – as IFR materials are woven of a cloth that is “of a flame resistant fiber”. However you may have pyro dust or any other potentially toxic hazard that has attached itself to it during use on the road.

A cotton fabric would, or should, have been sprayed or dipped.  It could be a chemical from any number of different flameproofers. Even the most eco-friendly of chemicals aren’t going to be designed for use up against the skin.

Each flameproofing supplier mixes and make their own chemicals.  They have changes over the years as testing requirements have also changed. As such, something treated by a New York flameproofing service would be a different chemical to something treated by one in Los Angeles. I personally would not want to put any of these flame retardant fluid treatments “directly” against my skin or pack my lunch into a bag with a chemical treatment on it.

A poly mix fabric may have a chemical on it – that depends on many factors – most polyesters are treated with different chemicals to cottons!

In short – we suggest that ANY backdrop you intend to put into the “consumer marketplace” be sent off to a commercial washer / launderer – and be vigorously laundered (several times – up to 5 washes may be needed to remove residue) to remove any and all chemical residue.  Despite laundering, and due to the potential risks involved with these types of chemicals, we don’t recommend re-purposing of backdrop materials into items that will be in contact with skin or food directly.

“But there are some companies and people on the internet that offer to do this………..!!!!”

Yes – there are some companies out there that do this type of thing.  Back in the day they were mostly recycling / repurposing VINYL banners and backdrops – which by the way would be the one and only printed product that would be relatively safe to re-purpose as there is little to no likelihood of a topical treatment having ever been applied to them. If you do decide to use one of the online companies to convert your old backdrops into saleable products for your fan club, we suggest that you insist they launder the goods prior to sewing them. Especially if you plan on putting them in the marketplace as tote bags. It would be a shame to be “doing good” and at the same time end up with a bigger issue.

When we treat and sell backdrops, they are sold with an intended use.  That is as a backdrop!  When you sell a tote bag, it is far more difficult…. As you can’t really sell it or gift it and say “oh, by the way – don’t put food in it, or your baby clothes….”.

SUGGESTION – maybe use them to skin outdoor patio umbrellas or something that will still be cool – but not so “close to the body”.  Just an idea 🙂

23 04, 2015

Thinking Beyond Poly

By |April 23rd, 2015|Education, Fabrics, Flame Retardancy|2 Comments

While many of our clients still prefer cotton when choosing fabric for custom stage curtains and backdrops, over the years, the use of polyester fabrics for stage and event drapes and soft goods has become increasingly popular.

But what you may not realize is that, while “polyester” is a standard term, there are a number of different “brand name” polyester fibers, including Avora® and Trevira®.

What differentiates Avora® and Trevira® from “plain old” polyester?  A major difference relates to the molecular structure of the fibers and how that structure affects the flame retardancy of the milled fabric.  With Avora® and Trevira®, an organic compound is added at the molecular stage, during the creation of the fibers themselves, thus making the resulting fabric inherently flame retardant.  By contrast, regular polyester does not undergo that same process, therefore the flame retardancy of polyester fabrics can vary.


This beautiful Grand Drape, constructed for Gridworks for Princess Cruises “Queen Victoria,” is made of IFR 26oz Velour, a Trevira® fabric.  Photo By: George Davidson of Gridworks.

Want to learn more?  Download our printable white paper, Stage Drapery Fabrics – Avora® and Trevira® Polyester

Questions on IFR vs FR Fabrics? See our whitepaper, Does “IFR” Mean it’s More Flame Retardant than “FR”?

Questions on Flame Retardancy Outside the US? See our whitepaper, “Flame Retardancy Regulations Throughout the World