Start with the environment
Consider exposure to moisture, chemicals, temperature and mechanical wear. These conditions help define the material grade and finish to discuss.
Define the opening and diameter
Mesh opening and wire diameter work together. Specify the opening, required dimensions and any critical tolerances rather than relying only on a general mesh description.
Share the intended use
Screening, filtration, fencing and reinforcement have different requirements. Tell your contact how the material will be used, and share drawings where available.