There is a version of frame type in the quotation and a different one in the goods. The gap between them is a tolerance, and it is where the money is.
What frame type actually controls in shutters
L for inside recess, Z for outside recess with trim coverage.
The consequence is that this figure sets the floor for everything downstream: the process, the price and the failure mode all follow from it.
For Plantation shutters, the working range is L-frame / Z-frame / deco frame. Inside that band the choice is commercial; outside it, the product changes category and so does the price.
How to choose a frame type option
| Option | What it changes in shutters | When it is the right choice |
|---|---|---|
| L-frame | The lowest-cost option in the family. Louver sag is where it usually ends up. | Cost-led programmes with a short service life |
| Z-frame | The volume middle: enough margin for process variation without paying for headroom the end product cannot use. | Most repeat programmes, and the safest default |
| deco frame | The top of the family, where the process is controlled tightly enough to guarantee it. | A warranty, a tender, or a specification that cannot be renegotiated |
These are alternatives, not points on a scale. Frame type is chosen by the application rather than by price, and a supplier who quotes one option as if it were interchangeable with another is quoting a different product.
The middle is where most programmes should sit, and it is the hardest position to defend in a price meeting because it has no story attached to it.
The figure that decides the outcome is not frame type itself but the tolerance around it. A supplier who quotes L-frame / Z-frame / deco frame without a tolerance has not quoted a specification, and the first lot will define the tolerance for you.
How to measure frame type
The reference method here is Hinge cycles, run to 10 000 open/close, with an acceptance of no torque loss. The method is the easy part; sampling and conditioning are where reports diverge.
Take samples from the beginning, middle and end of the run. A single sample from the top of a roll tells you about the top of that roll, and frame type varies more across a run than most buyers expect.
Record the measured value rather than pass or fail. A marginal pass on frame type tells you the process is running at the edge, which is the information you need before the next lot rather than after it.
Frame type does not stand alone
Frame type moves with material (basswood / PVC / MDF / hybrid) and with panel configuration (1-4 panels per opening). Tightening one usually costs money in another, and a supplier who accepts every tolerance without comment has either not understood the interaction or is planning to substitute.
When you change frame type, re-check the two neighbours before you approve the sample. Most of the samples we re-make are caused by a change in one figure that was not followed through.
The clause to write for frame type
The line below is the version we can quote against without inventing anything. Frame type appears with a tolerance and a test, not as a standalone number.
Plantation shutter, basswood, 89 mm louver, L-frame, 3 panels, hidden hinge, light gap <= 3 mm, painted to RAL 9010, moisture content 8-12 %
Write it once and reuse it. The buyers who avoid claims are not stricter than everyone else; they send the same well-written clause every time.
When frame type goes wrong
Louver sag. Wide louvers droop in the middle.
The cause is usually louver width beyond the material’s stiffness, or too few tilt pins.
The test that catches it: Load test at the louver centre; measure deflection.
What to specify instead: Limit louver width by material: 89 mm for basswood, 114 mm only with a reinforced core.
Note that the fix is a specification change, not a negotiation. By the time the claim is made, the only remaining lever is who pays for it.
Four questions about frame type, before you order
- What tolerance do you hold on frame type, and what did your last three lots measure against it?
- Which method do you use for hinge cycles, and which laboratory signs the report?
- When frame type falls outside L-frame / Z-frame / deco frame, do you rework, downgrade, or ship and hope?
- Which of material or panel configuration would you move first to hit a lower price?
The answers are more useful than a certificate, because they show whether the process is controlled or merely inspected. Full ranges for shutters are on the product page, and the measurement regime is described on the quality control page.
Questions buyers ask before ordering
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.
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.
- Frame type: agree the test method with the number. Two labs, two methods, two answers, one argument.
- Material (basswood / PVC / MDF / hybrid): state where in the band this order sits. The middle of the band is not what a tolerance is for.
- Panel configuration: the figure you will accept inside the 1-4 panels per opening band, the tolerance on it, and the method used to measure it.
- Hinge (hidden / aluminium / stainless): name the number, not the word. If the answer only repeats the band, ask which point inside it is being offered for this order.
- Deviation rule: anything outside the agreed bands is reported before shipment, not after arrival.
- Packing and marking: shipping mark, roll or carton count and the tolerance on quantity, since a short shipment is a claim too.
- Who inspects: third-party, in-house or none, decided in advance, with the AQL level written down.
Three questions, and the answers that separate mills
If the shutters figures on this page is going to be decided on a call, take these three questions into it.
| Question | Answer that should worry you | Answer that holds up |
|---|---|---|
| Which test catches hinge pull-out? | “We have never had a complaint.” | Louver deflection — on the production lot, with the acceptance figure written into the report and not into the email. |
| May I see a report for a lot you shipped last month? | “That is confidential customer information.” | A redacted report, which carries every number that matters and none of the customer’s identity. |
| Where in the basswood / PVC / MDF / hybrid band will this order sit? | “In the middle, normally.” | A stated target and the readings behind it. Material drifting inside the band is how a conforming lot still fails. |
Need frame type specified and tested against your end use?
Send a window schedule or a single set size and we will return a quotation with the loading plan, the safety standard that applies to your market and the lead time for the colour you need. Catalogue and current price list on request.
Related reading
Catalogue and current price list · Neutral packing and private label · Consolidation, documents and lead times
