Hi,
The blank valuation type stock quantity and value is actually the mean or consolidated stock quantity and value of the valuation types under the main material. It doesnt have effect in most of the transactions; only in some reports where there is no valuation type field, the blank val type will be considered.
Suppose your material is extended to 2 val types and each have 20 units in stock. Then the blank val type will show stock of 40 in material master.
Hope its clear.
Regards,
AKPT