Last updated: October 2026
By Jack Lv, General Manager — 925 sterling silver and GRA moissanite manufacturing in Foshan since 2011
A tech pack is the written specification a factory prices from, and it is what separates a quote you can rely on from a guess. To be quotable it must state dimensions with tolerances, metal and its silver content, stone material with size and grade, the setting method, plating type and thickness in microns, surface finish, a weight target range, packaging, and the acceptance criteria. A render alone fixes none of those, which is why it produces both a wide price spread and a bulk run that does not match the sample.
A tech pack is the document that describes a piece precisely enough for someone who has never spoken to you to make it; it is neither a mood board nor a sales sheet. Every line in it maps to a cost line in the quote, which is why a picture-only brief comes back either as a wide range or as a tight price for a different object.
A tech pack, sometimes called a spec sheet or a technical file, is the document that describes a piece precisely enough for someone who has never spoken to you to make it. It is not a mood board and it is not a sales sheet. Every line in it corresponds to a cost line in the quote, which is the real reason it matters: a specification you leave open is a cost the factory has to estimate, and an estimate is a risk that gets priced in or gets resolved later at your expense.
Readers who only supply a picture usually receive a quote built on guesses. Either it comes back as a wide range, because the factory had to estimate the weight, the stone size and the setting, or it comes back tight on a piece built differently from what the buyer had in mind. Both outcomes cost time, and the second costs a season.
A complete pack also protects the second order. A specification that was written can be repeated, audited and re-quoted by another supplier. A specification that lived inside a photograph cannot.
Enough that the factory never has to estimate: construction, dimensions with tolerances, alloy and content, stone material and measured size, setting type, plating metal and thickness, weight range, packaging and acceptance criteria. Missing any one of them turns that line into a guess, and guesses are where quotes stop being comparable.
| Section | What to state | Why it moves the price |
|---|---|---|
| Dimensions and tolerances | Every measurable dimension with a unit and a plus-or-minus tolerance, and which of those dimensions are critical | Sets the metal volume and the casting yield, and decides whether a piece passes or fails inspection |
| Metal and purity | 925 silver, meaning 92.5% silver with the remaining 7.5% usually copper, or another alloy you actually want | Material cost is the largest variable line in a silver quote |
| Stone material and size | Material name, size in millimetres, grade, cut and the number of stones per piece | Silicon carbide, ZrO2 and other simulants are priced differently and cannot be substituted silently |
| Setting method | Prong, bezel, channel, pavé or flush, and the setting pattern across the piece | Hand setting is labour time, and a more protective setting costs more to execute |
| Plating | Plating metal and thickness in microns, plus what is plated and what is left bare | Thicker plating costs more material time and changes how the piece feels |
| Surface finish | High polish, satin, brushed, matte or a mix, and which surfaces take which finish | Additional polishing stages are additional labour and additional handling risk |
| Weight target | A target weight per piece given as a range, not a single figure | Weight is the material cost. A drift upward during tooling rewrites the price. |
| Packaging | Box, pouch, care card, labels, and the position and size of any logo or stamp | Custom print and custom inserts are separate setup items |
| Acceptance criteria | What you will accept and what you will reject, and how it will be measured | Turns a quality argument into a measurement with a boundary on it |
An image communicates appearance, not construction, and construction is what a factory prices. From one render, one factory can reasonably plan a hollow stamped build and another a solid cast build — different objects at different prices.
A photorealistic image communicates appearance. It does not communicate construction, and construction is what a factory quotes. From the same image, one factory can reasonably plan a hollow stamped build and another a solid cast build, and those are different objects at different prices and different weights. Neither is wrong. The specification was simply absent.
The same applies to the stones. An image shows a size impression, not a measurement. A factory guessing at stone size has to guess at the setting, the drill or seat, and the labour per stone, and every one of them appears in the quote. When the guess is low the price looks attractive; the correction arrives during sampling or, worse, during production.
Give every dimension a unit and a plus-or-minus tolerance, then mark which dimensions are critical and which are cosmetic, so the factory protects the ones that matter. If you already sell a physical reference piece, send it: measuring a real object removes more uncertainty than any drawing.
Give every dimension with a unit and a tolerance, using a plus-or-minus figure rather than a range you describe in words. Then mark which dimensions are critical and which are cosmetic. A factory that knows the ring inner diameter is critical and the decorative scroll is not will protect the first and accept normal variation in the second, which is how a reasonable price is reached without sacrificing fit.
Casting shrinks as it cools, and the shrinkage has to be planned around rather than discovered later. If you have a physical reference piece you already sell, say so and send it, because measuring a real object removes more uncertainty than any drawing. If you do not, agree in writing which dimensions the factory will confirm on the sample, and confirm them with calipers when the sample arrives.
Where a dimension cannot reasonably be held, say which way you would rather it missed. A tolerance with a preferred direction is far more useful to a factory than a tolerance with none.
State the metal as an alloy and a content, not a marketing word: 925 silver means 92.5% silver with the remainder usually copper, and that remainder affects colour, hardness and how the piece takes a setting. Name the stone material rather than a trade name — moissanite is silicon carbide at 9.25 on the Mohs scale, cubic zirconia sits at 8 to 8.5 and diamond at 10.
State the metal as an alloy and a content, not a marketing word. In the trade, 925 silver means 92.5% silver, with the remaining 7.5% usually copper, and the recipe of that remainder affects colour, hardness and how well the piece takes a setting. If you need a different alloy or a harder wearing build for a particular product line, say so in the pack rather than after the sample.
For stones, name the material rather than a trade name. Moissanite is silicon carbide with a hardness of 9.25 on the Mohs scale. Cubic zirconia is ZrO2 and sits at 8 to 8.5, and diamond is 10. Those differences matter for how a stone survives everyday wear, and they matter more for price. Nabest works in VVS moissanite, purchased as cut loose stones and set into finished pieces, and moissanite reports from GRA are issued per stone rather than per order, so if you need documentation for individual stones say so before production and not after.
Specify the setting by name and pattern. A bezel protects a stone edge and costs more to execute cleanly than a simple prong setting. Pavé and channel work trade labour for stone security. Say how many stones sit on the piece, how they are laid out, and whether they need to be matched for size and colour across a run, because matching is work and work is priced.
Four attributes: the plating metal, the thickness in microns, which surfaces receive it, and the colour tone. Thickness is the one most often left out and the one that decides how the piece looks after a season of wear, so ask for the figure rather than an adjective.
Plating has several attributes worth writing down: the plating metal, the thickness measured in microns, and which surfaces receive it. Thickness is the one buyers most often leave out, and it is the one that decides how the piece looks after a season of wear. Ask for the figure rather than an adjective, and put it in the pack so that the quote, the sample and the bulk order all refer to the same number.
The honest trade-off is that a thicker plating costs more and takes longer, and it can slightly change how a piece feels and how sharply a detail reads. That is not a reason to avoid it. It is a reason to decide it deliberately rather than to let a factory choose for you.
Colour should be anchored to something physical. Approve a plated sample or a standard colour reference as part of the specification, and say whether the reference applies to the whole piece or only to the visible face. Finish should be described surface by surface, and say explicitly how the interior, the underside and the contact points are to be treated.
Give weight as a target range per piece and say whether it is measured before or after stones are set, because weight is the material line in the quote. Packaging belongs in the same document since it is quoted too: box, pouch, care card, labels, and where the hallmark or logo goes on the piece.
Give the weight as a target range per piece rather than a single figure, and say whether the range is measured before or after stones are set. Weight is the material line in the quote, and a hollow construction and a solid construction can look identical in a photograph while weighing quite differently. A range gives the factory room to cast sensibly and gives you a defensible boundary at inspection.
Packaging belongs in the same document because it is also quoted. List the box, the pouch, the care card, any label or barcode requirement, and any printed or embossed branding, and state where your logo or hallmark goes on the piece itself. If the piece is to be stamped, decide the position and the size before sampling so the stamp is part of what you approve rather than a change afterwards.
Because that section decides disputes: the measurable checkpoints, the tolerance on each, and the defect classes you will not accept, such as a loose stone or plating visibly thin at an edge. Our own runs pass four gates — IQC, IPQC, FQC and OQC — with XRF, a precision balance and calipers on the bench, so the criteria can be measured rather than argued.
The last section of the pack is the one that decides disputes: what you accept and how it is measured. Write down the measurable checkpoints, the tolerance on each, and the defect classes you consider unacceptable, such as a loose stone, plating that is visibly thin at an edge, or a dimension outside its stated tolerance. If you work with an acceptable quality limit, define it as the defect level you agree to accept and state where it applies, because a limit with no definition is not an inspection criterion.
Nabest works to a four-inspection system, IQC then IPQC then FQC then OQC, covering incoming material, in-process work, final product and outbound shipment, with an XRF spectrometer for material verification, a precision balance, calipers and magnification on the bench. That equipment matters to a tech pack because it means the specification has to be written in terms those instruments can check: a percentage, a mass, a dimension, a magnification observation.
Tie the pack to a sealed sample. Once you approve a sample, it becomes the physical version of the document, and later production is compared against it. Sampling at Nabest takes 5 to 7 days and bulk production runs 15 to 20 days after approval, so the specification has to be settled before sampling starts, not refined during it.
Tolerances, plating thickness in microns and the acceptance section go missing most often, followed by measured stone size and the basis of the weight figure. Each omission moves a decision from you to the factory.
You can, and many first orders start that way, but expect a wider price and a slower start. A picture leaves construction, stone size, plating thickness and weight open, so the factory has to estimate every one of them. Adding a dimensioned drawing, a stone specification and a weight range is usually a shorter conversation than correcting a sample that was built on guesses.
No. A dimensioned drawing, a hand sketch with measurements, or a physical reference piece can all be worked from, and a factory can usually turn an approved drawing into a production file. A CAD file simply removes one round of interpretation, which is why it usually shortens both the quote and the sample.
Give a tolerance on every dimension that matters, mark the critical ones, and say which direction you would rather a miss fall. You do not need to tolerance decorative detail, but you do need to say that it is not critical, because otherwise a factory will either assume everything is critical or assume nothing is.
Yes, because packaging carries cost and setup just as the piece does. A branded box, a printed care card and a stamped logo are all quoted lines. Putting them in the same document keeps them inside one quote and one sample round instead of becoming a second negotiation after the metal work is already approved.
Metal and purity, dimensions with tolerances, stone material with size and count, setting method, plating metal and thickness in microns, finish, a weight target range, packaging contents, quantity per size or colour, and the acceptance criteria. That set covers every line a silver jewelry quote is normally built from, and it fits on a page alongside the drawing.
Send your design, size and quantity — factory quote back within 24 hours. Reference: General enquiry