Christian Supply had actually contacted me over a year ahead of time, so we had plenty of time to discuss details. They asked if I could create a rendition of a particular painting by a (living) artist named DuBois. It depicted a classic nativity scene.
I was to build the mosaic onsite as an "in-store promotional" kind of thing.
I provided various preview images at differing sizes and colors, and the store requested that I go with the scheme that would construct a 90" by 70" version of the mosaic using 8 colors (the basic six plus orange and tan).
A few years ago it would have been unthinkable to build a mosaic that required thousands of orange and tan 1x1 bricks, but these days, with the existence of Bricklink and such, it is actually feasible.
Before going to South Carolina (the Palmetto State, by the way), I prebuilt the orange, tan, and green pieces; mainly to make sure I had enough in stock, but also because I was only going to have three days to finish the mosaic onsite. I debated going ahead and filling in all of the numerous red pieces too (6000+ red 1x1s involved), but decided to wait.
The backing of the studs-out mosaic consisted of 12 extra large baseplates and 36 large (green) baseplates.
Even after these several years of mosaic building there's still room for me to learn things. In this case I learned just how much of a hassle it is to build these mosaics while they hang on a wall. Normally I cover a baseplate completely and then add that section to the other completed baseplates as they hang up, but in this case Christian Supply had asked that I hang the whole thing up first and add to it (to give an overall concept of final size from the very beginning).
It's amazing how much harder it is to follow building instructions while standing up. Not to mention not having the pieces within immediate reach as you do while sitting at a table or on the floor or wherever.
The whole building process, onsite, took much longer than I was used to. I was actually afraid I might not finish in the three days time (there were about 30,000 pieces total in the mosaic, maybe a third of which had been prebuilt). I began to wish that I had prebuilt the red pieces along with the orange, tan, and green.
I did get the mosaic completed on time, but it required my showing up at 7:30 each morning, two hours before the store opened, and it was a total of 34 hours of work (34 for hours within a three day timeframe, mind you).
Besides that, the event was fairly typical. People came by to watch me build. Kids went "oooh" and "ahhh". My fingers got sore.
One young lady actually showed up and asked that I sign the current issue of GAMES magazine (for which I did the cover); that was cool.
Here are some pictures of the project at various stages: