Paul,

I have not experimented with placing warp biased cloth across the grain, but it's a valid concept. Practical considerations make it less attractive, but it's still valid. For example, in the case of chasing minimum possible weight, we know that a single layer of 3.2 oz glass is sufficient for paddling in open water, but provides minimal protection from hard contact (rocks). The lightest warp biased cloth I've found readily available is 3.7 oz (http://www.fiberglasssupply.com/Product_Catalog/Reinforcements/Glass_Fabrics/glass_fabrics.html Style 1522). So, there wouldn't be a weight advantage from using that warp biased cloth alone to achieve minimum weight.

For less than minimum weight builds, some warp biased cloth across the grain makes sense from an understanding of the mechanical behavior of typical lay-ups. But we don't have practical analytical methods to help us understand how much benefit it would provide, or how much we should use.

Sam