The two cheapest options, and they fail in opposite conditions: one dents, the other yellows.
The decision in one paragraph
Paulownia blinds and slats and PVC blinds and slats are not substitutes in the way a price list suggests. paulownia is specified for slat thickness at 2.5-3.2 mm; PVC slats is specified for uv stabiliser at required, stated in phr. If your product depends on the first, the second is a compromise regardless of price.
The two cheapest options fail in opposite conditions: one dents, the other yellows. Which one is cheaper depends on where it will hang.
Both are legitimate for the value end, and neither should be sold as a contract product.
Side by side on the numbers that matter
| paulownia | PVC slats | Comparison |
|---|---|---|
| Primary use | Value residential windows | Bathrooms and wet rooms |
| Decisive parameter | Slat thickness: 2.5-3.2 mm | UV stabiliser: required, stated in phr |
| Second parameter | Moisture content: 8-12 % | Yellowing resistance: QUV 300-500 h, dE <= 3 |
| Usual MOQ | 300-500 sets per colour | 500-800 sets per colour |
| Production lead time | 25-35 days | 20-30 days |
| Characteristic failure | Denting | Yellowing |
Where paulownia wins
Needs more thickness than basswood to reach the same stiffness. Paulownia moves faster than basswood, so equalising matters more, not less.
The failure you are buying protection against is denting: slats show dents and marks after a season of cleaning and use. If that is the failure your customer will report, paulownia is the cheaper decision even at a higher unit price.
Where PVC slats wins
Without it, white goes yellow and colours fade within a season outdoors. The test that separates outdoor-grade from indoor-grade PVC.
Against that, PVC slats fails as yellowing. White slats turn cream within a year in a sunny window. The question is whether your programme can absorb that failure, and whether the saving per unit exceeds the cost of one occurrence.
How to decide without a trial order
- Write the service conditions for the end product, including washing and climate.
- Name the failure you cannot accept, in one sentence.
- Ask both suppliers for the same test on that failure, on production material.
- Compare landed cost including the expected claim rate, not unit price.
- Record the decision and the reason, so a cheaper quote later does not reopen it.
Specifications for both are on the paulownia page and the PVC slats page. If you send the end product description, we will tell you which one we would specify and what we would test first.
Questions buyers ask before ordering
Why is paulownia cheaper than basswood?
Faster growth, higher availability and lower density, which also lowers freight. It is not a cheaper process; it is a cheaper raw material with different mechanical limits.
Will white PVC yellow in a sunny window?
Not if it is properly stabilised. Ask for a QUV 300 h report with dE <= 3. Without that report, assume it will yellow.
Total cost over three years
| Line | paulownia | PVC slats | Note |
|---|---|---|---|
| Purchase | Higher unit price | Lower unit price | Paid at the order |
| Claims | Lower if the spec matches | Higher if the failure mode hits | Paid 6-18 months later |
| Replacement | Rare | Likely once | Paid in the season you cannot supply |
| Rework at your factory | Lower | Higher if the material behaves differently | Paid in labour |
The two materials fail in different places, and that is the deciding factor. paulownia fails as denting; PVC slats fails as yellowing. Choose the failure you can detect early, because an early failure is a rework and a late one is a claim.
A trial that answers the question in one container
- Take production samples of both, in the exact construction you would order.
- Run the end-use process: light weight, low price.
- Test the single failure you cannot accept, on both, with the same method.
- Put the result next to the landed cost including the expected claim rate.
The specification to send, for either
Whichever way you decide, send the same line to both suppliers so the quotes are comparable. For paulownia:
Paulownia venetian blind, 50 mm slat, 2.8 mm, density 0.25-0.32 g/cm3, moisture 9-11 %, sanding sealer + 3 coats, warp <= 2.0 mm/m, cordless to EN 13120
And for PVC slats:
PVC venetian blind, 50 mm slat, 2.0 mm wall, UV stabilised, QUV 300 h dE <= 3, HDT >= 65 C, co-extruded woodgrain, cordless to EN 13120
Where both appear in the same product
Most assembled products use both materials rather than choosing one. paulownia typically carries value residential windows, while PVC slats carries bathrooms and wet rooms. The decision is therefore not which one to buy but which one to put where the load and the wear are.
A practical rule: put paulownia at the point where denting would be expensive to fix, and PVC slats where yellowing is visible early enough to rework. That single sentence resolves most specification arguments between the two.
Three questions to ask both suppliers
- Which parameter would you change to hit a lower price, and what does it cost? The answer shows whether the supplier understands their own trade-offs.
- What is the MOQ per colour, and what does a repeat order need? paulownia typically runs 300-500 sets per colour; PVC slats runs 500-800 sets per colour.
- What would you refuse to guarantee, and why? A supplier with no limits is either new or not answering.
Three questions, and the answers that separate mills
If the comparison you are making 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 denting? | “We have never had a complaint.” | Warp — 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 0.25-0.32 g/cm3 band will this order sit? | “In the middle, normally.” | A stated target and the readings behind it. Density drifting inside the band is how a conforming lot still fails. |
Failure modes, and the test that catches each one
A specification only earns its keep if it names the failure it prevents. These are the two that matter for the comparison you are making.
| Failure | What triggers it | Test to demand on the production lot |
|---|---|---|
| Colour variation | Heartwood and sapwood mixed, or two species mixed under one name. | Coating adhesion — cross-hatch; acceptance no lift |
| Denting | Low density and a soft early-wood layer. | Janka hardness — ASTM D143; acceptance report value |
The other two, with acceptance numbers attached, are in the full failure analysis for paulownia. A supplier who cannot name the mode he sees most often is describing a catalogue, not a process.
Choosing between these two for a live programme?
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
- Slat width in Paulownia blinds and slats
- Moisture content in Paulownia blinds and slats
- Paulownia blinds and slats Specification
Catalogue and current price list · Neutral packing and private label · Consolidation, documents and lead times
