印籠 (inrô) pill box/nested boxes, handy chart by fantastic Edo-lover Nadeshico Rin.
Inrô were first used during Sengoku period by men to carry their personal seals (印鑑 inkan) and thick red ink (朱肉 shuniku). It was then used to carry medecines (薬 kusuri), such as pills (丸薬 ganyaku), powders (散薬 sanyaku), or decoctions (煎じ薬 senjigusuri). Slowy people also added any small trinkets which could fit in.
First carried by samurai class, it then spread to chônin commoners in the Edo period. Many shapes existed, and inrô boxes could be made from many materials depending of their owners’ fortune, from paper to precious ivory. Often beautifully decorated, their designs could include raden (mother of pearl inlays), or makie (gold powder).
On the right, you can see the different part of an inrô:
根付 (netsuke) carved toggle (sometimes very intricated miniature sculptures), slipped into the obi belt
紐 (himo) cord, holding everything together
緒締 (ojime) string-fastener bead, could be made from precious coral or as decorated as netsuke
飾結び (kazari musubi) ornamental knot, at the bottom
紐通し孔 (himodôshiana) lacing hole, to thread the cord into the boxes
蓋鬘 (futakazura) top piece, lid of the box
段 (-dan) row of boxes, ex. 一段 (ichidan) first row
Main types of inrô shapes existed, with of without visible lacing holes (紐通し付き himodôshi tsuki = visible / 隱し紐通し kakushi himodôshi = hidden). Rin details following styles on the left:
杏仁形 (kyônin gata) apricot seed shaped
楕円形 (daen gata) ellipse shaped
胴張形 (dôbari gata) hull shaped
丸角長方形 (marusumi chôhôkei) rounded rectangle shaped
長方形 (chôhôkei) rectangle shaped
角切形 (sumikiri gata) cut-corners shaped