A sheet of labels as produced by the printer before it is converted (cut) into separate blocks (q.v.) or matchlabels.
It is recommended that a printer’s sheet remain uncut unless you can arrange to have it accurately cut into separate matchlabels using a guillotine. Badly cut labels, especially with scissors can be made worthless.
It is possible that whole printer’s sheets can be more valuable than the sum of the individual labels in the sheet.