Original Gum

Original gum — abbreviated OG or o.g. — means that a stamp retains the gum applied during its manufacture. It is one of the most frequently used condition terms in stamp descriptions and one of the most important for unused stamps.

Gum Descriptions

• Full original gum — all the original gum is present.
• Part original gum (POG) — some original gum remains.
• No gum (NG) or without gum — none remains.
• Regummed (RG) — new gum has been applied. See regummed.

These may be combined with hinging terms: OG NH (never hinged), OG LH (lightly hinged), OG HR (hinge remnant).

Why Original Gum Matters

A stamp with full original gum demonstrates that it has survived in its issued condition. For classic stamps, which often lost their gum through soaking or deterioration, full original gum can be scarce and significantly increase value. Catalogues often note when a price assumes original gum.

Identifying Original Gum

Each issue typically has a characteristic gum:

• Colour — white, yellowish, brownish or tinted.
• Texture and sheen — shiny or matte, smooth or streaky.
• Type — gum arabic, dextrin, PVA or self-adhesive.
• Cracking pattern — some older gums develop a distinctive craquelure.

Experienced collectors compare questionable gum with known genuine examples. Gum that extends onto the perforation tips, looks too fresh for its age, or has the wrong colour may indicate regumming.

When Gum Is Removed

With some classic issues, gum has been removed to protect the paper from cracking or tropical staining, and some specialists consider this acceptable. Nevertheless, a stamp without gum is valued lower than an equivalent with original gum, and it should never be regummed.