8.6 cm by 6 cm. Done on a scrap of animal skin parchment (not sure what critter; it was a gift), gilded with 23 karat patent gold with fish glue as a binder, and painted with gouache. Calligraphy & lines done in sumi ink.
I did this after work yesterday and finished it this morning, purely for no reason other than I didn't want to work on anything that I actually need to get done. I've also wanted to try making a tiny manuscript to scale, so I just copied an existing one word-for-word (though I guess lettershape-to-lettershape would be more accurate - I don't know latin and the source was hard to read, so half of this is illegible). Anyways, this is a 15th century French book of hours - part of Psalms 123 & 124. The translation as well as source pics are all on the website, so if you want to see what my derpy letter shapes are supposed to look like and translate to, here ya go: [link]
The calligraphy/illumination is off from the original by about 6mm. I may have been able to do it smaller with no lines, but when I lined it for the calligraphy it smooshed out on me without realizing.