Which materials, besides wheat/flour costs, were the primary targets for conservation via the ban?

Wax Paper and Alloyed Steel

The official rationale for banning pre-sliced loaves centered explicitly on conserving two specific materials critical for the war effort. First, sliced loaves generally required thicker wax paper wrapping to maintain freshness compared to whole loaves, thus increasing the consumption of this vital wrapping material. Second, the industrial machinery used for slicing consumed alloyed steel, a metal desperately needed for military production. The government estimated that halting the production of new slicing machines would save approximately 100 tons of this alloyed steel. While flour costs were a secondary consideration, the tangible material savings in wax paper and steel formed the core justification for Food Distribution Order 1.