Whether you feel inspired to scribble in the characters of Chuck Palahniuk or Lisa Frank, there’s a coloring book out there for you. The widely popular adult coloring book trend seems like it’d be great news for pencil companies, but the Independent reports that some major manufacturers are struggling to satisfy the demand.

Workers at Faber-Castell’s factory in Germany have been forced to run extra shifts in order to keep up with production. The world’s largest wooden pencil producer is reportedly seeing double-digit growth in artists’ pencils sales and has boosted its supply significantly compared to the previous year.

Faber-Castell isn’t the only company that’s been impacted by the fad—the European manufacturer Staedtler and Stabilo has reported a colored pencil shortage, as have suppliers in Brazil. According to The Washington Post, overall colored pencil sales spiked by about 26 percent in 2015—a significant change from the past three years, during which growth never exceeded 7.2 percent. In response to the increasing amount of adult customers, some companies like Crayola are now selling adult coloring books and pencils as a package deal.

Demand for higher quality pencils and larger sets has also risen. Sandra Suppa from Faber-Castell told the Independent, “People are now not satisfied with ‘just’ 36 colors and we are noticing a trend in people preferring bigger sets of 72 or even 120 colors for coloring.”

If you've somehow avoided joining the coloring book bandwagon, it’s not too late to start—just make sure to stock up on pencils while they're still on the shelves.

[h/t Independent]

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