Use a stock mould when the geometry already works
A stock mould can shorten the path to market when its capacity, neck, stability, visual proportion and carton envelope fit the brief. Differentiation can then come through coating, frosting, printing, a chosen component stack or secondary packaging. Confirm that the available bottle can accept the desired finish before treating it as a production-ready base.
Open a new mould only with an engineering brief
A custom glass mould needs more than a beauty sketch. Define nominal and full capacity, height, footprint, glass weight range, neck finish, cap proportion, label or decoration areas and the distribution route. The glass engineer can then review radii, base design, wall transitions and manufacturability before tooling is quoted.
Create separate approval gates
Review the technical drawing, mould sample, component fit sample, decorated sample and golden sample as distinct approvals. Each answers a different question: geometry, appearance, compatibility, process repeatability and production reference. Keeping those gates separate reduces the chance that a visually attractive sample is treated as evidence of full packaging performance.