The 'found' buttons on Eggs's Blue costume consisted of a coat check disc, poker chip, old typewriter key, rusty nut, two clock cogs, an old bead, and a button.

It took about 3 hours to print a single Eggs face on a 3D color printer, and about 3 more hours to process and prepare it for shooting on stages.

A principle character in The Boxtrolls could have as many as 8,000 3D-printed replacement faces. A range of individual brow and mouth pieces allowed a character to have approximately 1.5 million possible facial expressions.

The VFX (Visual Effects) department created a unique population of CG characters to supplement the main puppets, including 81 CG Boxtrolls and 96 CG humans. It took approximately 3 months to create each CG character, from design to shot production.

A single shot that was 56 seconds long took 4 months for a single animator to shoot. Including blocking and rehearsal time, this animator worked on the same shot for over 5 months.

Construction of the three dozen unique sets required 18 carpenters, 18 model builders, 6 riggers, 12 scenic painters, 11 greens artists, and 10 sets dressers, who worked together over a period of roughly 18 months.

In order to fill a 70-foot movie theater screen, Eggs's face had to be magnified 560 times. Great care was taken to make sure there were no inconsistencies or blemishes in the finished faces that would be only too obvious at that magnification.

Over 8,500 stage-quality replacement faces were printed for The Boxtrolls, roughly half of which were for Eggs, the main character. His largest kit of faces consisted of 311 unique mouth parts.

The hair on the puppets' wigs was made completely out of sustainable, all-natural hemp, which was then combed, cut, bleached, dyed, and glued into over 144 different heads. More than 120 pounds (or 4,800 feet) of hemp was used—enough to cross 13 football fields.

Silicone, which was used in puppet head and body fabrications, starts as a liquid and turns solid through a chemical reaction. Everyday household material used to cast and seam the silicone puppets included cellophane, Vaseline, pantyhose, felt, and face powder.