Qualitative teaching companion to the six design rules. Feature geometries are illustrative only — not universal minimum feature sizes: real feasibility windows (walls, holes, drains, spans, tolerances) are material-, grade-, orientation-, and provider-specific and are settled by engineering review and fired test coupons. Verdicts assume a typical dense technical ceramic on each route; binder-jetting guidance assumes a sintering-densified workflow — infiltrated and reaction-bonded variants follow different rules.