By Robert Taylor

Stamp collecting is a hobby that has been with us for well over 150 years.  During that time, interesting new terminology has been introduced for all who undertake this hobby.

In this article, I will list what I think are pretty important terms for collectors to know and understand.  As many of us are aware, we can also call upon that magical website called “Google” to give us further definitive information on just about anything including stamp terminology.

Below is a simple list of common terms encountered within stamp collecting.  They are:

Adhesive Stamp:    A modern day type of stamp that has an adhesive backing rather than the gum backing.

Back-Of-The-Book:            Stamps that are listed in the back of a stamp catalog such as the popular Scott Catalog.  Examples are air mail, revenue stamps, officials, hunting permit stamps such as duck stamps, etc.

Cancellation:            A hand stamp, machine stamp or pen stamp across the face of the stamp to render it invalid for further postal usage. 

Centering:     How the image sits on the stamp.  Stamps printed off to the side, onto the perforation, etc. are not as desirable as evenly centered stamps.

Commemorative Stamp:              A postage stamp marking a special anniversary or event.

Definitive Stamp:                A postage stamp intended to remain in everyday use for a considerable time period.

Fault:              A factor that can decrease the value of a stamp such as a missing corner, a stain, a crease, etc.

Gum:              The adhesive substance brushed or printed onto the back of postage stamps which when moistened, will cause the stamp to stick to an object such as a postal letter.

Line Pair:      A line of ink printed between two coil stamps.  Normally this line is right up through the perforation between the two stamps.

On-Off Paper:          “On paper” is simply the stamp remains attached to paper such as an envelope or a piece of the envelope.  “Off paper” means the stamp has been removed from an item such as an envelope.

Perforation:              Rows of punched holes separating stamps from one another in a sheet.  The perforations can have different sizes and it’s very important to be aware of perforation size differences.

Plate Block:              A block of 4, 6 or more stamps with a plate serial number in the margin or “selvage” area.

Selvage:        A portion of the stamp that extends beyond a perforation.  This can be easily seen when you look at a sheet of stamps and all the outside stamps around the sheet should then have selvage.

Space Filler:             A stamp so badly damaged or so heavily cancelled that images on the stamp cannot be seen.  Stamps from Great Britain often are heavily cancelled.  This stamp sells inexpensively and serves to fill an album space until a better stamp comes along.

War Stamps:           Postage stamps issued in wartime and so inscribed such as “War Tax”. 

Watermark:             Semi-transparent pattern impressed into paper during manufacture as a guard against forgery.  Today, few postage stamps are watermarked but many, many early stamps were definitely watermarked.  Just like many items we see today, there is forgery in stamps also.

Should you have a question about any stamps you have, just email me at

Happy collecting!