There is a beautiful image of a pyxis, a piece of ancient Greek pottery, on the British Museum website. I believe its name translates as compass box. [Correction: its name is the same as a constellation whose name translates as compass box but a pyxis is a container with a lid.] Its design shows a språng loom with a partially-completed piece of språng. It is museum number 1907,0519.1. The description notes that it's a "sprang frame, used for making hairnets."
You can get a sense of the loom's size by comparing it to the women shown. The frame's ratio of width to height, excluding the bit at the top, is 1:1.5, very close to phi, the golden ratio.