It’s easy to make flash paper yourself. Flash paper readily ignites with friction, heat, or a spark, producing a flash of flame with essentially no smoke or ash. It’s great for magical tricks and chemistry demonstrations. It has practical applications too, as a lacquer, nail polish base, film base, guncotton, artificial silk, and filter material.
Here are three easy ways to make homemade flash paper, including safety and storage tips.
What Is Flash Paper?
Flash paper is a common name for the polymer nitrocellulose. Other names include cellulose nitrate, guncotton, collodion, pyroxylin, flash cotton, and flash string. The starting material is cellulose, which is polymer found in plants. Sources of nearly pure cellulose include cotton balls, cotton t-shirt fabric, paper, paper towels, saw dust, or starch. Historically, a mixture of nitric acid and sulfuric acid nitrates the cellulose. The chemical bonds between the nitrogen and oxygen atoms release a lot of energy when broken, producing the flash.
Alexander Parkes first made nitrocellulose in 1862, which he called Parkesine. The most common method making it is Christian Friedrich Schönbein’s procedure, which calls for 15 parts acid to 1 part cotton.
Here is the usual reaction:
3HNO3 + C6H10O5 → C6H7(NO2)3O5 + 3H2O
Note, sulfuric acid is not required. However, it acts as a catalyst that makes the nitronium ion, NO2+. The first order reaction proceeds via electrophilic substitution at the C-OH centers of the cellulose molecules.
- Ideally, make flash paper under a fume hood. Assuming you don’t have one of these at home, perform the project outdoors. The acids fume, so avoid breathing the air in the immediate vicinity.
- Protect yourself from acid splashes. Tie back long hair, wear safety goggles or glasses, wear long pants and closed-toe shoes.
- Disposable gloves are good, but choose ones that resist the acids. For example, vinyl gloves offer protection, but latex gloves aren’t effective.
- Don’t use metal bowls or utensils. Glass is best (especially Pyrex). Don’t use wood, because it’s cellulose. Plastic spoons are okay, but they may discolor or melt.
- Mixing acids and making nitrocellulose releases heat. Before you get started, make sure you have ice. Alternatively, make nitrocellulose when it’s very cold outside.
- Make up a mixture of baking soda in water. Baking soda is a weak base that neutralizes acid. Use it for neutralizing spills, rinse water, etc.
Method #1 – Make Flash Paper With Sulfuric and Nitric Acid
The classic reaction involves cellulose, sulfuric acid, and nitric acid. This protocol produces the highest quality flash paper. Either cotton balls or tissue paper work well for this procedure. Sulfuric acid is available from home supply stores, both as concentrated acid or as drain cleaner. Nitric acid is available online.
- 30 ml 60% nitric acid
- 80 ml 98% sulfuric acid
- 5 grams cotton (or other form of cellulose)
- Ice bath
- Mixture of baking soda (sodium bicarbonate) and water
If you’re using concentrated nitric acid and concentrated sulfuric acid, a good ratio is 5 parts nitric acid to 4 parts sulfuric acid.
- If you’re using paper, cut it into small sheets (the final size you need). This applies to any of the three methods.
- Prepare an ice bath. This is just a large container of ice and water. Rest a glass bowl or pan on the ice to chill the reaction.
- Carefully pour the nitric acid and sulfuric acid into your glass container. Either swirl to mix or stir with a glass rod.
- Submerge the cotton or paper in the acid mixture. Use a glass rod or plastic spoon and make certain all of the material is wet.
- Let the cotton or paper soak a minimum of 15-20 minutes or as long as 1 hour. The purity of the cellulose (cotton or paper) determines the final color. Pure cotton stays white or slightly yellows. Toilet paper becomes pale brown.
- Transfer the paper into a container of water. Use glass or plastic tongs and neutralize any spills with the baking soda and water solution. Let the paper soak in the water about 5 minutes. At this point, you are finished with the acid mixture. Dilute it with water and neutralize it with the baking soda solution before rinsing it down the drain with plenty of water. Ideally, use pH paper and test the neutralized acid to make sure it is close to neutral. If it’s still acidic, add more baking soda.
- Pour off the water from the paper and add more rinse water. Repeat the process. The rinse liquid contains much less acid, so it’s probably fine just pouring it down the drain, but you can collect all the rinse water in one large container and neutralize it with baking soda before disposal, just to be safe.
- Neutralize any residual acid on the paper by soaking it in the mixture of baking soda and water. The flash paper is safe to touch now.
- Finally, rinse in distilled water. (Tap water works, but the final product doesn’t burn as cleanly.)
- Either store the flash paper wet (for later use) or leave it on a paper towel overnight to dry (for immediate use).
Method #2 – Make Flash Paper With Potassium Nitrate and Sulfuric Acid
If you have trouble finding nitric acid, there is an easy alternative. Use potassium nitrate or saltpeter instead. The pure chemical is sold as stump remover in home supply stores, plus it’s available online.
- 50 g potassium nitrate
- 80 ml sulfuric acid
- 5 gram cotton
- Prepare an ice bath.
- Set your glass container in the ice bath. Dissolve 50 grams of potassium nitrate in 80 milliliters of concentrated sulfuric acid.
- Soak 5 grams of paper or cotton in this liquid for 1 hour.
- Rinse three times with water.
- Neutralize the paper with baking soda in water.
- Rinse the paper with water.
- Store it wet or else dry it for use.
Method #3 – How to Make Flash Paper Without Acid
The third way of making flash paper does not involve acid. The resulting paper isn’t quite as good as the kind made using acid, but it’s quite serviceable. You can use metal containers and utensils for this method, if you like.
- 2 tablespoons (18.5 g) boiling water (distilled is best)
- 10 grams ammonium perchlorate
- 5 grams cotton
- Dissolve 10 grams of ammonium perchlorate in 2 tablespoons of boiling water.
- Soak 5 grams of cotton or paper in the liquid for 1 hour.
- Let the flash paper dry completely before use. (No rinsing or neutralization steps here.)
How to Store Flash Paper
Commercial flash paper comes wet in a sealed package and has a shelf life of around one year. Once you open the package, store leftovers sealed either in the original package or a zip-lock plastic bag.
For optimum safety, store homemade flash paper wet and sealed in a plastic bag. Do this after the step where you neutralize the reaction with baking soda. Dry flash paper lasts much longer than a year, but it degrades over time and becomes more dangerous. If you store dry flash paper for any length of time, only store very small quantities in a cool, dark, dry location away from any flammable materials. For example, store a sealed bag in a humidor or inside a freezer.
How to Use Flash Paper
Only use the smallest amount you need for a particular demonstration or magic trick. Ideally, keep your flash paper wet until a day before use. Then, take it out of storage and let it dry completely. Don’t rush the process using heat because of the risk of ignition. If you have leftover paper, dampen it with distilled water and return it to its storage bag.
Flash paper ignites with a match or ignition switch, burning pretty much instantly and producing little to no smoke or ash.
How to Know When It’s Expired
Depending on the purity of the starting material, homemade flash paper may be pure white or slightly yellow. If it starts turning brown or rusty or becomes gooey it’s no longer safe. Eventually, it runs the risk of self-igniting. Dispose of expired flash paper by placing it on a fire-safe surface or holding it with tong and igniting it with a long-handled lighter.
- Braconnot, Henri (1833). “De la transformation de plusieurs substances végétales en un principe nouveau.” [On the transformation of several vegetable substances into a new substance]. Annales de Chimie et de Physique. 52: 290–294.
- Pelouze, Théophile-Jules (1838). “Sur les produits de l’action de l’acide nitrique concentré sur l’amidon et le ligneux.” [On the products of the action of concentrated nitric acid on starch and wood]. Comptes Rendus. 7: 713–715.
- Schönbein, Christian Friedrich (1846). “Ueber Schiesswolle” [On guncotton]. Bericht über die Verhandlungen der Naturforschenden Gesellschaft in Basel. 7: 27.
- Urbanski, Tadeusz (1965). Chemistry and Technology of Explosives. 1. Oxford: Pergamon Press.
- Worden, Edward Chauncey (1911). Nitrocellulose Industry. Vol. 2. D. Van Nostrand Company.