Why Tolerance Matters More Than Price
A production-level view from real factories
Most PET felt suppliers say the same thing:
“±3 mm tolerance is industry standard.”
Honestly, when we first entered this industry, we said the same.
On paper, it sounds reasonable.
On drawings, ±3 mm looks small.
But when PET felt is used as a backing board for wooden slatted acoustic panels, this number often becomes the starting point of production problems — not the end.
This article is not about theory.
It is based on what we see working with European manufacturers running real production lines.
When “Industry Standard” Meets Real Production
In many factories, PET felt is not a decorative product.
It is part of a system.
Wooden slatted panels are produced with:
- Fixed mold dimensions
- Fixed slat lengths (2400 mm or 600 mm)
- Fixed groove spacing
- Fixed assembly sequence
Once the mold is set, nothing wants to move.
PET felt, however, is a compressed fiber material.
Even with CNC cutting, dimensional variation is part of reality.
On paper, ±3 mm looks harmless.
Inside a mold system, it is not.
Small deviation does not disappear.
It accumulates.
Tolerance vs. Mold System
Tolerance by itself is not the enemy.
The problem starts when tolerance meets a fixed mold system.
If the PET felt board is slightly wider, it resists entering the mold.
If it is slightly narrower, slats begin to drift during assembly.
The deviation does not stay at the edge.
By the last slat, alignment is already off.
No one stops the line for this.
Stopping the line costs more than fixing the problem.
So workers adjust.
They trim.
They push.
They compensate by hand.
Each action is small.
Together, they quietly slow production.
This is why some manufacturers are very strict about width tolerance — sometimes even more than thickness.
Not because they are difficult.
But because their mold systems leave no room for interpretation.
The Hidden Labor Cost of ±3 mm
±3 mm looks small.
It usually costs nothing on a quotation.
On the production line, it rarely stays free.
Tolerance problems do not appear as big failures.
They appear as extra labor.
A worker checks alignment again.
Another trims a few millimeters.
Someone adjusts slat spacing by hand.
Seconds are lost.
No one records them.
No one reports them.
But they happen on almost every panel.
Over one shift, the loss is invisible.
Over one week, it becomes measurable.
Over one project, it shows up as higher labor cost and lower output.
From the supplier side, the product is “within tolerance”.
From the factory side, it creates extra work.
And extra work is the most expensive cost in manufacturing.
A Real Discussion About Tolerance
One Nordic client came to us.
Their first question was not price.
Not delivery time.
It was: What is the tolerance of your PET felt?
They use standardized molds and fixed slat lengths.
For them, tolerance directly affects production flow.
Their requirement for a 600 × 600 mm PET felt panel was:
- Thickness: 9 mm ±1.0 mm
- Length: 600 mm +1.0 / -0.0 mm
- Width: 600 mm +1.0 / -0.0 mm
The order quantity was large enough to make many suppliers accept immediately.
We didn’t.
We explained the reality:
Even CNC cutting machines have tolerance.
±1.0 mm is achievable in real production.
+1.0 / -0.0 mm is not realistic at scale.
To make this clear, we produced 1000 panels and randomly inspected 200 pcs.
98% fell within ±1.0 mm.
The client accepted this result.
To reduce their production pressure, we also makes some adjustments for their future using.
This discussion was not about perfection.
It was about predictability.
Why Some Clients Never Complain?
Not every client complains when tolerance creates problems.
The most experienced ones often don’t.
When issues appear on the line, the first response is internal adjustment.
Workers trim.
Supervisors reorganize tasks.
Production keeps moving.
From the outside, everything looks fine.
The supplier may never hear about it.
Over time, production managers notice patterns:
- This supplier needs more adjustment
- This material slows the line
- This batch requires rework
None of these issues are big enough to trigger a complaint.
But when the next project comes, purchasing compares again.
Same drawing.
Similar price.
Similar delivery time.
One supplier creates less friction.
That supplier wins.
No argument.
No warning.
In manufacturing, silence is often the final feedback.
Why Serious Manufacturers Talk About Tolerance Before Price?
Serious manufacturers don’t ignore price.
They just don’t start with it.
Production does not run on purchase orders.
It runs on time, labor, and repeatability.
A lower material price looks attractive at the buying stage.
But production costs appear later — quietly.
Factories that care about tolerance usually have:
- Standardized molds
- Fixed labor planning
- Clear output targets
- Limited room for improvisation
In this environment, tolerance is not a quality detail.
It is a production variable.
When tolerance is clear, production can be planned.
When tolerance is vague, production relies on adjustment.
Adjustment means people.
People mean cost.
This is why serious manufacturers talk about tolerance before price.
Not because they want perfect material.
But because they want predictable production.
Tolerance is not a theoretical number.
It lives on the production floor.
Some suppliers talk about it to close a deal.
Some manufacturers talk about it to protect their factory.
When both sides understand tolerance the same way, price discussions become easier.
Because real cost is already under control.