Where this usually helps
Material decisions usually matter most for custom parts, prototypes, gifts, and practical short-run prints. Some jobs are appearance-first, while others need durability, heat resistance, or better structural behavior.
Many buyers do not start by knowing the exact material. They start by explaining the use case. That is usually the right order, because the intended use should drive the material recommendation.
Custom enquiries usually involve at least one non-standard condition: exact dimensions, special wording, file adjustments, fit requirements, or a small-batch need that should not be pushed through a generic online store flow.