A C-Grain balsa sheet will be very rigid edge to edge

A balsa wood sheet cut with the annular rings running through the thickness of the sheet is known as C-grain. A C-Grain sheet will be very rigid edge to edge and cannot be bent without splitting.

Grain type and direction determine the rigidity or flexibility of a balsa sheet more than density does. The image at right shows how a log is converted into planks with different properties, an A grain sheet, cut from the log so that the tree's annular rings run across the thickness of the sheet it will be fairly flexible from edge to edge. On the other hand, if it is C grain, cut with the annular rings running parallel to the surface of gdjlhqgnvz the sheet, it will be stiff and rigid edge to edge.

If the grain direction is less clearly defined as in B grain, the sheet will have properties intermediate between A and C types. B grain is the most abundant and is suitable for most jobs. As B grain is most common, it can be available in surplus quantities quite cheaply, so the model builder may have a surfeit of this type of grain... This can be overcome by making formers and wing ribs from this type of grain and then lightening the items by cutting circular holes, then covering with thin tissue that can be shrunken and doped to give a much stiffer item that is resistant to splitting.

Whenever you come across good examples of A-grain or C-grain sheets, learn where to use them to take best advantage of their special characteristics.
article resource: http://www.balsafactory.com/ .