Always read and follow the care instructions and any warnings on the garment label. And, follow the General Rules for washable fabric stain removal.
The best way to deal with crayons is to get advice right from the horse's mouth....Crayola! See their removal tips at their web site.
For another option, here's what another source says: Scrape excess crayon with the dull edge of a butter knife.
Wash in hot, soft water with soap, such as Ivory and 1/2 cup baking soda for 10 minutes.
If the stain remains, work soap paste into the stain. Wash 5 minutes. Rinse.
To remove any remaining color use bleach or color remover as safe for the fabric. Always test for color fastness.
CAMELBAK® SKIRMISH PACK
This pack, made with 500D CORDURA® Classic fabric, is durable with some serious features. Its sleek composite MOLLE paneling provides secure attachment for pouches and gear. Skirmish features the Mil Spec Antidote® Lumbar Reservoir. The exclusive reservoir design moves the weight of the water onto the hips to ensure a comfortable/ergonomic load-carry as well as lower center of gravity. The full clamshell opening allows for easy access to the main compartment. Learn more about this technology. Shop for this technology>
MANHATTAN PORTAGE PRALL BACKPACK
Made out of lightweight and durable CORDURA® Lite fabric, this unique bag can be worn over the shoulder that includes a strap clasp to eliminate extra straps from hanging. It also features reflective tape that will definitely make you stand out in a crowd. Unique one strap backpack design featuring both drawstring and buckle closure 3M™ reflective strip for extra visibility. Learn more about this technology. Shop for this technology.