Rouletted in coloured lines is a variety of rouletting, and always so termed, in which the slits or cuts are made by means of type ("printer's rule") a little higher than the clichés or stereos composing the plate, and which cut into the paper under the pressure of the printing-press.
Safety paper.—See Paper.
"Seebecks."—The late Mr. N. F. Seebeck, the contractor to various South American Republics had an arrangement under which there was a new issue of stamps every year, he to retain for his own benefit any demonetised remainders of the previous set: stamps provided under such conditions are called after their originator.
Se tenant.—A French expression signifying that the stamps referred to have not been separated: usually employed in reference to an error, or variety, when still forming a pair with a normal stamp.
Serpentine roulette.—See Percé en serpentin.
Sheet (of paper).—There are three "sheets": a mill-sheet, as manufactured; a sheet as printed, which may be, and often is, less than a mill-sheet; and a "post-office" sheet, either the whole or an arbitrary part of a printed sheet, so divided for convenience of reckoning.
Silk-thread paper.—See Paper (Dickinson).
Single-line perforation.—See Guillotine.
Spandrel is the term for the triangular space between a circle, oval, or curve, and the rectangular frame enclosing it.
Specialising.—To develop in a collection a complete record of the inception, history, and use of the stamps of a particular country, or group of countries, in the fullest and most detailed manner. In contradistinction to Generalising (which see).