CAD will draw anything. Metal will not always cooperate. These seven details are the usual reasons a beautiful render turns into a remake, and each is easy to catch before casting.
1. Walls that are too thin
A shank or a hollow section that looks elegant on screen may be too thin to cast fully, to polish, or to survive daily wear. Ask your manufacturer for their minimum thickness for the metal you chose, and design above it.
2. Prongs with no margin
Fine prongs photograph beautifully and snag, bend and wear. Check their thickness and height against the stone they hold, and the metal: platinum, 18K and 14K do not behave alike.
3. Stone seats cut to the exact size
Stones are never exactly the size on paper, and metal shrinks slightly as it cools. A seat drawn to the exact millimetre is a seat that will be too tight or too loose. Seats need a working tolerance.
4. Hairline detail that polishing erases
Fine engraving, tiny texture and razor-sharp edges soften when a piece is finished and polished. If a detail matters, make it deeper or bolder than it looks necessary.
5. Sharp internal corners
Sharp inside corners collect polish compound, hold stress and fill in when casting. A small radius costs nothing in appearance and helps the piece cast and wear better.
6. Enclosed hollows that cannot be cleaned
Closed cavities can trap casting material and are hard to finish or inspect. If a hollow is part of the design, ask how it will be vented and cleaned.
7. Comfort that was never checked
The inside of a band, the edges that touch the finger, and the way neighbouring stones sit against an adjacent ring are invisible in a front-view render. Ask for a printed model to check them, as in our note on render versus wax model approval.
A habit worth building
Before approving a file, ask one question: Is anything in this design at or near your minimums? A good manufacturer will answer plainly, and the answer is cheaper than a remake.