What Is Meant By "Gum Rippling?"

Hello! I am looking at a copy of Germany SC B119. The description says "horizontal gum rippling." Is this considered a defect? Or is this normal for German stamps of the 1930s? Any insight would be appreciated. Thanks.

Gum rippling is an overall linear pattern impressed on the gum. You can find this on some postwar and 'Bundesrepublk' definitives (Heuss) along with smooth gum varieties in some cases.

If you hold the mint stamp under a light and tilt it, you will be able to see if it has horizontal or vertical rippling, or smooth gum. The rippling is lost when the gum is removed, such as on used stamps.

Thanks very much bookbndrbob. That is very helpful. Is rippling considered a fault that would reduce the value of a stamp of this era?

No, and in the stamp you mention, the gum riffles are mentioned because they are found in either a vertical or horizontal pattern. If you have such a stamp with smooth gum, then it has been re-gummed. They were only made with the riffling.

Vertical riffling on this stamp catalogs almost 3 times as much as horizontal riffling.

Got it. Thanks so much for sharing your knowledge.

Many German stamps from this period have gum ripples. The Michel catalog lists them with suffixes "x" or "y" -- x for vertical ripples and y for horizontal ones. This particular stamp is Mi 671, and has values for MNH in the 2019 specialized catalog of 80 euro for 671x and 30 euro for 671y.

The ridges can be difficult to see on this issue. A good trick is to very slightly bend the stamp, and look at the gum with strong side lighting.

It is interesting that Michel lists prices for mint and used copies of both types (horizontal and vertical) of gum rippling.
In the notes section of the catalogue there is mention that the steel rolls used to break the gum "...caused rippling in the gum and occasionally, the paper.".
As well, sometimes due to a poor roller set the rippling may be non-existent or barely visible on some stamps.

Many German collectors are more interested in gum types than North American collectors. They collect by gum type. Been down that rabbit hole.

It's not an easy task to check gum types on used stamps but they give it a shot.

Dan