These ‘backmarks’ can provide useful information for dating the buttons, as details of the various companies, and when they were operating, can be found in contemporary trade directories and other documentary sources.
The marking is invariably produced by die stamping, which is an inherent part of the manufacturing process, and backmarks produced in this way continue to be used to the present day.
Where it has not been possible to reconcile such differences, the various dates and date ranges encountered are all shown in the applicable ‘Date’ field.
The backmarks consist of the company’s name (or initials) alone, or the name and address together.
In general, dates should be regarded as approximate, and not exclusive unless the context indicates otherwise.
It is also the case that there are some differences in respect of dating between the secondary sources that have been consulted.
The company kept detailed records on its work force.
Among the employee records are lists of employees by age and years of service, of nurses and nursing volunteers during the influenza epidemics of 19, and reports on accidents by gender from the company's hospital.
If details seem rather sparse in some cases, it should be borne in mind that the information shown might have been gleaned from a single button or a single documentary reference.