The only way I know to print by batch Sales Order is the following :
1) Sales order List
2) Click on "Print Sales Confirmation"
3) Leave blank the field "SO No"
4) PRINT
Expected result => You should print every SO for the same Customer
But, if you follow the same path, you will see that the "SO No" will be the same on all your printouts.
Has anyone found a way to do this ?