The present invention consists of a jewelry storage and concealment device having rigid frame which is substantially thin and planar and which is suitable for attachment to a standard hanger, over which any ordinary article of clothing may be placed, for concealing the device between clothes in a closet. The inkjet ink contains: a polyamic acid having a weight-average molecular weight of 50,000-500,000; one or more of an amic acid compound and an amic acid compound, in which the amic acid compound is prepared from a compound having two or more anhydride groups and a monoamine, and the amic acid compound is prepared from a diamine and a compound having one anhydride group; and a solvent. A consensus subsystem can select a host server from the migratable target list.