Plantation shutters Specification: What Each Number Actually Changes

Two suppliers can quote the same plantation shutters at the same headline figure and deliver different products. The difference is in the numbers nobody puts in the quotation, and in the tolerance behind the number that is quoted.

Why the headline number is the least useful one

Every quotation leads with louver width. It is easy to compare and it is the number the factory can hit most cheaply. But it tells you almost nothing on its own: louver width sets the frame, and the parameters below set whether the product survives its first year in service. A buyer who compares only the headline figure is buying a sample, not a supply agreement.

For shutters, the practical rule is to fix the headline figure at the level your product needs and then spend your negotiating attention on material and panel configuration. Those two are where cheap goods differ from adequate goods, and they are usually absent from the quotation sheet.

The numbers that decide performance

Read the table as a set of trade-offs rather than a checklist. Moving any single line usually costs money somewhere else, and the cheapest way to hit one figure is often to let another slip.

Louver width

Typical range: 63 / 89 / 114 mm. 89 mm is the residential standard; 114 mm reads as premium and needs a deeper frame.

Frame type

Typical range: L-frame / Z-frame / deco frame. L for inside recess, Z for outside recess with trim coverage.

Material

Typical range: basswood / PVC / MDF / hybrid. Wood is premium; PVC suits wet rooms; MDF is mid-market.

Panel configuration

Typical range: 1-4 panels per opening. Panel count drives hinge count and light-gap performance.

Hinge

Typical range: hidden / aluminium / stainless. Hidden hinges cost more and eliminate the visible line.

How to write a shutters specification that protects you

A specification is only useful if a substitution becomes visible. That means writing the construction and the performance together, and naming the test that proves each one. For shutters, the clause has to pin material and panel configuration, because those two separate a compliant lot from an adequate one:

Plantation shutter, basswood, 89 mm louver, L-frame, 3 panels, hidden hinge, light gap <= 3 mm, painted to RAL 9010, moisture content 8-12 %

Note what is missing from that line: adjectives. No ‘high quality’, no ‘premium’, no ‘export grade’. Every clause is either a number with a tolerance or a named test. If a supplier cannot quote against a line written this way, that is information about the supplier.

Where the specification usually breaks down

The first failure is visible light gaps. Daylight shows through between panels and frame. The cause is usually frame out of square, or panels machined without a jig. The test that exposes it before you order: Assemble on a flat table, measure gaps at three heights.

The second is louver sag. Wide louvers droop in the middle. It comes from louver width beyond the material’s stiffness, or too few tilt pins. Test with Load test at the louver centre; measure deflection. and write the result into the purchase order, not just the enquiry.

Both failures share a pattern: they appear months after delivery, they are hard to attribute, and the cost lands on the buyer rather than the mill. That is exactly why the test belongs in the specification and the report belongs in the shipment file.

What to put in a shutters enquiry

1. End use and the conditions, which together decide where material has to sit inside basswood / PVC / MDF / hybrid.
2. The one figure that must hold, with light gap named as the proof.
3. Quantity per colour and per delivery, against a typical MOQ of 100-300 panels per finish.
4. Destination market, because compliance changes the construction, not just the paperwork.
5. A physical standard viewed under a stated light source, not a screen proof.

With those five points we can quote against a real requirement instead of a generic range. Full ranges sit on the shutters page, and the manufacturing side of the same question is on our quality control page.

Questions buyers ask before ordering

Which louver width should I stock?

89 mm covers 80 % of residential demand. 114 mm is a premium upgrade that needs a deeper frame, so stock it only if you sell design-led projects.

Can shutters be fitted inside a recess?

Yes with an L-frame. Outside the recess with a Z-frame. The measuring method differs and getting it wrong is the most common installation complaint.

What light gap is acceptable?

3 mm or less between panels. Buyers inspect this first, and it is the clearest signal of machining quality.

Failure modes worth a clause in the purchase order

Claims rarely come from a batch that was obviously wrong. They come from a louver width figure that sat inside the quoted band and outside what the product needed.

The other two, with acceptance numbers attached, are in the full failure analysis for shutters. A supplier who cannot name the mode he sees most often is describing a catalogue, not a process.

Seven lines that turn a quotation into a specification

Most post-delivery arguments are not about quality. They are about a document that never said which figure would be measured, on which instrument, at whose cost.

1. Frame type (L-frame / Z-frame / deco frame): fix the value per shipment, and state who pays for the re-test if a lot lands outside it.
2. Material: basswood / PVC / MDF / hybrid is not an answer on its own. Ask for the last three lots’ actual readings and the spread behind them.
3. Panel configuration: agree the test method with the number. Two labs, two methods, two answers, one argument.
4. Hinge (hidden / aluminium / stainless): state where in the band this order sits. The middle of the band is not what a tolerance is for.
5. Deviation rule: anything outside the agreed bands is reported before shipment, not after arrival.
6. Packing and marking: shipping mark, roll or carton count and the tolerance on quantity, since a short shipment is a claim too.
7. Who inspects: third-party, in-house or none, decided in advance, with the AQL level written down.

Related reading

• Panel configuration in Plantation shutters
• Plantation shutters
• How to Test Shutters Before You Commit to a Container