Creating beautiful scenery on a budget often requires Scenics to paint on lightweight soft goods like muslin, silk, lace, and burlap. Unfortunately, these fabrics are also very combustible and have a long record of contributing to some of the worst theatre fires in history. With so many products and tools available to us (and because it is a fire code issue!) there is no reason why we shouldn’t be adding the time and budget to properly flame retard our soft goods – painted or not. In this article, we’ll break down what products are available for treating your fabrics and help you identify which one to use on each substrate.

One of the most important tips:

⊗ Don’t use the wrong product on the wrong substrate.

For many applications, the best choice is to treat your scenic element with one product either in its raw form (before you add any paint), or at the end after all the pretty stuff is done.  What you use to FR wood is not the same as cotton muslin, china silk, or paper.

Knowing which product to use on which substrate is pretty daunting, if you don’t have a lot of background knowledge of products and materials. To simplify this process, Rosco created a handy reference chart;

The fire retardant experts at Turning Star manufacture Rosco’s range of Roscoflamex products, and they are used all over the entertainment industry, from community theater to Broadway, theme parks to tv/film production, and more. I always get great info from their customer service number about which Flamex products to use on what, and I recently ran a bunch of small sample tests on common fabrics that I wanted to share. I will be talking about common application methods on various substrates and fabrics, how to test your work when you are done, and the results of my testing.

2 Common Methods of Application: Spraying and Dipping

Before applying any flame retardant product, it is highly recommended that you work in a well-ventilated area and protect yourself from overspray with appropriate PPE gear, which includes clothing that covers bare skin.


This is often the most popular method due to the square footage of fabric and substrates we need to treat. Spraying involves loading the proper type of Flamex into a garden sprayer and then applying it liberally to the scenery or drop. The goal is total saturation. Because some fabrics are naturally hydrophobic, liquids tend to just bead up on the surface and don’t soak in right away, this is when using a broom or brush to help spread out and push fire retardant into the material helps avoids holidays. Two light passes of FR with the second happening before the 1st has completely dried is also highly recommended as it helps the second coat actually penetrate the substrate.

It is recommended that you treat your soft goods before you start painting and then size with starch after your application. But be cautious, as painting on FR treated fabric has been known to change the color of paints and appear splotchy until more coats of paint are added. Read more about that here!

Because of all these headaches, many Scenics will elect to flip a drop on to its face and apply a good layer of FR to the backside AFTER they have painted the drop.  The reason for flipping is that there is a risk of the Flamex leaving a subtle shiny sheen and we don’t want to risk ruining our hard and beautiful work.

It’s worth noting here that the main component of many FR’s can be corrosive if left in a metal sprayer for too long. The high nitrogen content will also kill grass and other plant life if spraying is done outdoors.


This involves getting a large plastic bin or bucket and submersing your material in flame retardant before laying it out on plastic to fully dry. Although the amount of Flamex needed for this method can be more than just spraying, it can a great method for ropes and open weave products like erosion cloth so that you know you have gotten every nick, nook, and cranny that spraying can miss.

Flame Test Procedure 

After the application of any FR product, it is crucial to test a sample to ensure that your goods have been effectively treated.

Flamex, like other flame retardants, are only effective when applied properly and in sufficient quantities. You should always test your work before loading it into the performance space.

Performing a flame test on your actual piece of scenery or drop will, at best, leave burn marks and at worst fail, meaning that you’ll watch your work go up in flames. The best practice is to create a separate sample piece to test with that was treated exactly the same way as your real piece, to test with. Pro-Tip; keep your samples handy just in case the local fire marshal pays a visit. That way they can test your sample instead of your scenery too. Some shops sew a sample piece about 12” x 12” onto the drop or curtain for testing purposes, about head height or a little higher is good. That way it’s clear which sample goes with which drape or drop. It’s right there and doesn’t get lost. If it’s at the top of a 20’ or 30’ high drop, no one will see it and it will be forgotten.

The “12/2” Testing” Procedure

1. Before performing your own test, make sure that the material and substrate have fully dried and cured. Many FR flame retardant products need up to 24 hours to cure depending upon the fiber characteristics of the substrate they were applied to.

2. Work in a draft-free area, and keep clear of away from other combustibles.

3. For fabric testing, it is recommended to use a piece that is, at minimum, 1/2 in x 4 in (12.7mm x 101.6mm). The fabric sample can be suspended lengthways by using tongs or spring clips.

4. Using a wooden match, position the bottom edge of the fabric 1/2 in (12.7mm) above the bottom of the flame.

The test FAILS if after 12 seconds of exposure, the match is removed from the sample and there are no more than 2 seconds of after-flame.

2.0 seconds or less = pass
2.1 seconds or more = fail

The test ALSO FAILS if flaming materials that break off or drip from your sample continue to burn for more than 2 seconds after they reach the floor.

NOTE: Fire regulations vary widely. Be sure that your treated materials meet the standard which applies to your venue. For an accurate look at the codes and standards that fire marshals use to test fabrics, you can visit the National Fire Protection Association’s website and obtain a copy of the NFPA 705.

For testing methods of other substates –  we recommend you consult with your local fire marshal directly.

It’s good practice to keep written records of your methods, samples, and etc. It’s the law that your flame retardancy effectiveness needs to be ‘maintained’ and most FR manufacturers advise treatment every 3 to 5 years.  It is also important to remember that Roscoflamex products, and many other brands as well, are water-soluble and are easily removed when exposed to water. It is also recommended that all treated fabrics be dry cleaned, and if you paint over FR treated goods, you should test and re-treat as needed.

A note about compliance:  The products mentioned and used in this article meet fire-retardant standards as established by NFPA, ASTM, ANSI, and UL and have been approved by the CA Fire Marshall and New York City Fire Dept. These are important things to research when choosing any brand of FR product.

Flame Test Results

When creating my testing samples, I used sample sizes larger than what is required, a stopwatch for timing, and if I ever felt a test got out of hand too fast I pulled my match away sooner and was quick to put out with water.

Painted Muslin Samples

I tested the NFR painting sample from another previous article Paint Off.

As you can see from the video below the un-treated material failed hardcore.

I used a small garden sprayer to spray one section of the back and another section of the front with Flamex NF to see if there was a noticeable difference in effectiveness or distortion to my painting.   The front treated section did have a subtle shine to it, so that is a thing to consider if deciding to flip a drop to paint. Both passed my test on the first try.

Poly Silk

Polyester Silks can lead to confusion as to what product is best to use. Should you use Flamex DF for delicate fabrics so that it keeps its flexibility, or do you go with Flamex SF because it’s synthetic?  So I tested both! I noted that both products did make the fabric samples ever so slightly crunchy and kept their wrinkles more- but they still fluttered nicely in the air as desired. I applied the FR with a spray method and both products passed on the first try. I did find, however, that the flame on the DF sample extinguished a little bit faster and with less damage to the fabric. 


Wow! Did you see how fast the untreated sample went up! This is why if you can’t purchase a pretreated FR burlap – you should definitely treat your own!  Flamex WD  (Wood) has been recommended to me in the past for products like burlap and erosion cloth, and I was curious as to why it was a better choice than the  Flamex NF (Natural Fiber)  that I’ve used in the past so I did a little research.  After comparing the Turning Star SDS’s of both products I found that the WD version has more “proprietary blend” and ammonium sulfate in the mix than in the NF version. It’s this difference that will help me choose both the product and my methods easier: do I want to do one treatment with WD or two with a NF?

I used the spray method, testing both the WD and NF.  And although I thought I had gotten them incredibly saturated, apparently I did not, which is why I am glad I tested.  The Flamex WD passed the first time, but the NF failed. After retreating my NF sample with a second coat, I found that it was a  “stiffer and more crunchy” than the WD version however it did finally pass.

Bonus fun time video – I tried to make the WD treated Burlap fail on purpose and it just refused!


I included rope because in my career, about every other year, I do a show where hemp style rope is a major component of the visual design and it should be treated. My samples for untreated rope failed several times because it would consistently continue to smolder after the 12/2 time, and the one time my camera was misbehaving it went up like a candle.  I used the Dipping method and once again compared the two types of Rosco Flamex; Flamex WDand Flamex NF.


Because it makes a great curtain material, lace is often used as a set dressing.  I had no idea what type of lace I had found, or if it was already treated with an FR product, so I tested a sample before I did anything. Watching it drip melty and firey bits was not only fun but also helpful, as it told me that I was working with a polyester blend.  (See here for an explanation of how to tell if a fabric is natural or synthetic…) One brushed-on coat of Rosco Flamex SF, and it easily passed the next test.  You can see the results in one of our previous photos.

In conclusion – we make pretty art for the enjoyment of others. Let’s keep everyone safe by taking the time – and making room in the budget – to protect us, our running crews, and audience members from accidental fires. I sampled just a small handful of common scenic fabrics in this article, but I would love to hear what other materials and substrates you have flame retarded, along with and the methods you’ve used to treat them, in the comments below.

And to see the other side of this conversation, check out this article about 7 Ways to Screw Up Your Flame Retarding.

 Angelique Powers has been painting for over 15 years and has an MFA in Scenic Art from Cal Arts.  Along with being the Charge Artist at Penumbra Theatre she also freelances and works with the University of Minnesota as an Adjunct Lecturer. She is currently most proud of her work as a Founding Member of The Guild of Scenic Artists and her work here on The Scenic Route.



Turning Star’s flame retardant products are used all over the entertainment industry, but did you know they offer more services? Along with laboratory testing services they can treat your large scale fabric projects with stain repellent and flame retardants.   We are proud to have them as a Guild Sponsor.


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