Opening a box of crayons and seeing white dust or powder covering your colors can be a concerning sight for many people. But is this mold?
Crayons cannot mold, but they can produce bloom. Bloom results from oxidization, pushing internalized paraffin wax from the crayon, producing white flecks commonly confused as mold. Bloom can be wiped off and should not cause alarm. Boxes and paper wrappings, however, can mold if wet and confined.
While bloom is not harmful, it still helps art supply owners to learn about what causes bloom and how to avoid it. This oxidation process is normal and natural, and should not be a cause for concern when it occurs. When there is true mold, as opposed to its commonly mistaken partner, bloom, this is NOT a result of the wax crayons. Rather, mold would need to grow on the paper wrappings or box to be present on the crayons.
What Causes Oxidation and Bloom in Crayons?
Oxidization is a natural process that occurs whenever something reacts to the oxygen in the air, bonds with it, and changes the chemical composition of the item. A common example is shown when air and water react with iron to form rust.
However, this is not the only type of oxidization that is present in the bloom on crayons.
Bloom, also known as efflorescence, is caused by an oxidizing process that occurs when wax comes into contact with air. Over time, the crayon wax can oxidize and the inner wax will rise to the top: creating bloom.
It is often seen in older, wax-based art supplies such as crayons and colored pencils. Bloom rises out of the crayon when natural components in the wax migrate to the surface, creating a dusty white coating.
Crayons can start displaying bloom in small spiderwebbing patterns of dust that often come out from the tips of the art supplies and spread down from gravity.
Is Bloom Harmful?
Wax bloom is completely harmless to humans. You can wipe it off with your bare hands if you please, it will not hurt or affect your skin.
The bloom comes from the center of the wax crayon. The material oxidizes over time, and rises out from the top. This means that the bloom is literally as potentially harmful as the crayon itself.
Removing Bloom from Artwork and Supplies
Crayons and Other Art Supplies
Bloom present on crayons or other art supplies can be brushed off with your hands, or a dry cloth. Crayon bloom can also be removed with water, but only when the paper wrappings are not present. This is important to note because unlike crayons themselves, paper wrappers can grow mold when wet.
It is more difficult to remove bloom from artwork than art supplies, but it is possible and there are several methods of bloom removal.
The use of spray fixatives is common in artwork, especially when using mediums that are more prone to smearing such as charcoal, chalk, or pastels. These mediums are also the most effective and permanent method of preventing bloom. These sprays are clear and apply a layer of lacquer or varnish over the artwork to “fix” the used mediums into place and protect the picture. The use of these fixatives can completely prevent bloom from arising.
Spray fixatives can be purchased online or in any art supply store. When unavailable, hairspray can be used as a substitute but is more likely to result in a slight yellowing of the paper over time.
The use of a dry cloth can be implemented to gently wipe the bloom off of an art piece, but it does bring some risk. Even the softest of fabrics can smear pigment, causing unintended alterations to the piece. In addition to this risk, wiping the bloom off of artwork does not guarantee that it will not return in time.
For a less sensitive removal, you can use a low-powered hair dryer or heat gun to gently heat the artwork and consequently remove the bloom sheen from the piece. Another option may be the use of an Icarus board, used as a heated surface for artwork. All of these heating methods will draw the bloom back into the artwork. It is best, however, to complete this process with a spray fixative for more permanent results.
How to Prevent Bloom
One of the best ways to prevent bloom is to use non-wax-based art supplies. When using wax mediums, however, the use of a finishing or fixative art spray can keep the bloom from forming on an art piece.
Crayons can be melted down and placed into silicone molds to reintroduce the wax and prevent bloom from occurring. This is not, however, a sure way to prevent the bloom permanently. It simply reduces the odds of it forming as quickly.
Temperature can often affect the speed at which bloom grows, the colder the temperature the faster it appears. Keeping your crayons in a relatively warm location (beware of melting) can slow the process of bloom production.
Real Mold on Crayon Boxes and Paper Wrappings
While it doesn’t occur on the crayons themselves, mold still can be an issue when a container is made of degradable materials such as cardboard or wood.
When dealing with bloom, inspect the containers for any signs of water damage and molding. If the package looks unharmed, then the dust is simply bloom.
If you think the box has molded, it is safer to toss the package. Mold is more likely to form on the paper wrappings and box when wet and left in an air-tight or enclosed container.
Humidity is a large factor in the speed of mold growth as well. Be aware of the humidity levels where you live. High humidity means that there is lots of moisture in the air, allowing mold to grow more easily. Dry areas that have lower humidity levels are less likely to grow mold, as they require an enclosed environment or container that can trap the moisture lacking in the air.