1. Why Did Separate Summer and Winter Cray-Pas Sticks Fail?
Cray-Pas first appeared in 1925 (Taisho 14), created by the Japan Crayon Syndicate, now known as Sakura Cray-Pas.[4] At the start of sales, this company released two types of sticks in the same colors: a soft one for winter and a hard one for summer.[5] Official articles from Sakura also state that the first products changed hardness significantly depending on the climate, so they made hard ones for summer and soft ones for winter.[6]
However, this split was unpopular with users. There were mix-ups during shipping, and complaints followed.[5] Three years later, in 1928, the manufacturing method was improved, and the sticks became usable all year round.[5][6] The background to this change is explained as the high oil content making quality easily affected by temperature.[5]
It is still strange that an art stick can act like a different tool depending on heat or cold. Let us look inside the stick step by step.
2. What Do Pigment, Wax, and Oil Do Inside a Crayon?
Crayons and Cray-Pas are made from the same three materials: pigment (the source of color), wax (which holds the stick's shape), and oil (which fixes the pigment to paper).[1] Among these, crayons have more wax and become slightly hard sticks. Cray-Pas have more oil and become soft sticks.[1]
For example, candle wax is hard and does not change shape when you hold it in your hand. Salad oil is runny. If you imagine mixing these two to get something of intermediate hardness, it becomes easier to understand the division: wax handles the shape, and oil handles the softness. However, this is just an analogy; the oil in Cray-Pas is not salad oil. In early Sakura products, a binder made from a mix of paraffin wax, stearic acid, and coconut oil is said to have been used.[2]
Japanese dictionaries explain crayons as sticks formed by dissolving waxes like paraffin, fatty acids, or wood wax, mixing in pigment, and solidifying them into a stick shape. The word "crayon" comes from the French word crayon, which means pencil.[3]
Here, explanations in different sources split. English Wikipedia distinguishes between wax crayons that use no oil and oil pastels that use non-drying oil and wax as binders.[2] Some Japanese explanations say that crayons also contain oil.[1] Specific numbers for the ratio of wax to oil do not appear in the available materials. The only thing we can say now is the trend: "more wax means harder, more oil means softer."
So, what advantages does a soft stick offer for drawing?
3. Why Are Soft Cray-Pas Easy to Use but Weak to Temperature Changes?
Crayons at the time were hard. While it was easy to draw lines, they were not good for filling large areas. Cray-Pas are soft and spread well, allowing you to draw both lines and areas. They allow colors to be mixed like powdered pastels, and layers can be built up or applied thickly like oil paintings.[5]
Sakura’s official article mentions that in the early 1920s, Japanese art classes centered on copying with cheap materials, making it difficult for children to express themselves freely.[6] Soft, spreading sticks were likely tools suited to that situation. However, this is the interpretation of the article’s author; the source does not explicitly state this.
In exchange, soft Cray-Pas had a weakness: they are easily affected by temperature. The reason for splitting them into summer and winter versions is thought to be that one stick could not maintain a usable hardness in both seasons. The detailed changes in manufacturing when they became year-round products in 1928 are not in the available materials.
By the way, there is another way to tell apart sticks containing oil: water.
4. Why Does Watercolor Paint Bounce Off Oil-Based Crayons?
If you draw on white paper with a crayon or Cray-Pas and then paint over it with watercolor, the painted area repels the paint. This is known as "resist painting." Crayons containing oil repel watercolor paints.[7] We will not go into molecular details, but the familiar property that "water and oil do not mix well" appears visibly on paper.
Whether paint is repelled depends on the type of paint. In the same verification test, acrylic gouache could be painted over a crayon without being repelled.[7] You need to look at each type rather than lumping them together as "water-based paints."
Another point: works made with oil pastels do not dry completely like oil paintings. English Wikipedia explains that this is because the oil used does not dry and harden.[2] This is a different property from oil paint, which dries and hardens.
The repelling property allows you to combine techniques with watercolors, but it can also make handling difficult during laundry or cleaning. Therefore, the "First Cray-Pas 6 Colors Washable with Water," released in January 2025, uses beeswax from beehives as a raw material. It is introduced as being washable off hands and bodies with water, and easily wiped off smooth desks or floors with a wet cloth.[8] However, the materials do not explain why beeswax makes it washable; the reason for its ease of removal is unknown.
5. How Can You Test Resist Painting with Crayons on Paper?
Try it on paper: Draw lines or circles with moderate pressure on white paper using a crayon or Cray-Pas. Then, use a brush to apply watercolor paint thinned with plenty of water over the drawing. The drawn parts will not accept the color, and your picture will emerge. Lay newspaper on the desk first.
If you have both types, draw lines with the same pressure and lightly rub them with your finger. Compare how they spread. By touch alone, you cannot determine the ratio of wax to oil.
If you read sources: Differences between crayons and Cray-Pas are in [1], the 100-year history is in [4], and the summer/winter story is in [5]. You might also check official manufacturer information to see if wax and oil ratios are published.