Audience: importers, distributors, wholesalers, and repacking companies who buy wallpaper adhesive powder (wallpaper glue powder) from China and need a way to compare suppliers — including us at Hangzhou KARN New Building Materials Co., Ltd. — on facts they can verify, not on marketing language.
A note on how this guide is written. This is a comparison framework, not a "best-of" ranking. Any factory you shortlist should be able to answer the same checklist below. We fill in our own product data as a worked example, so you can test the framework against the actual numbers on our product pages instead of taking our word for it. If a supplier refuses to give you the documents in Section 3, that is itself an answer.
1. What you are actually buying
Wallpaper adhesive powder is a dry, plant-starch-based powder that you mix with cold water on site (typically 1:25 or 1:30 powder to water by weight) to make a paste for hanging wallpaper. Two supply models exist:
- 20 kg bulk bags — raw powder for importers, distributors, and repacking lines;
- OEM / private-label small packs — 200 g, 300 g, 500 g, 1 kg (and custom sizes) packed under your brand.
Because the product is repacked and resold under your name, the two things that matter most are batch consistency and documentation — not a single "premium" label claim.
2. How to read the technical specs
Viscosity is the most-quoted number in this industry, and the most abused. A viscosity reading only means something when the test conditions are stated. When a supplier gives you a cP / mPa·s figure, ask for the full condition set:
| Parameter | What to ask |
|---|---|
| Concentration | Usually 5% solution (dry powder to water by weight) |
| Instrument | NDJ-8 / NDJ-8S / Brookfield, etc. |
| Rotor | Rotor number (e.g., No. 4) |
| Speed | rpm (e.g., 6 rpm) |
| Water & temp | Water quality and temperature at test |
| Time | Time after mixing when measured |
Worked example — KARN's own published reference values (verify on our product pages):
| Model | Base raw material | Reference viscosity (5% solution; NDJ-8 / NDJ-8S; No. 4 rotor; 6 rpm) | Positioning |
|---|---|---|---|
| K6 | Tapioca modified starch | 38,000 ±10% mPa·s | Ordinary grade; basic/price-sensitive markets, 20 kg distribution |
| 999 | Potato modified starch | 60,000 ±10% mPa·s | Main export model; most wallpaper applications |
| 999+ | Potato modified starch | ≈60,000 ±10% mPa·s | Anti-mold grade; humid rooms, premium OEM |
| KN-999 | Modified starch base (raw-material grade) | 40,141 mPa·s (measured; DS 0.3–0.4) | High-viscosity raw material for repacking and OEM |
Two practical takeaways:
- Different models, different test methods — never compare numbers across rows blindly. 999 at 60,000 mPa·s is not "stronger" than KN-999 at 40,141 mPa·s; they are different products measured for different jobs.
- Copy the exact condition set into your COA agreement. If you and the factory do not fix the concentration, rotor, and rpm, a later viscosity dispute has no shared basis.
3. The 8-point supplier verification checklist
Use this with every shortlisted factory, including us:
- Legal entity and factory identity. Ask for the registered company name and an address you can verify. Ours: Hangzhou KARN New Building Materials Co., Ltd. (杭州卡恩新型建材有限公司), No. 1, Wangjiamen, Huruixian Road, Chongxian Street, Linping District, Hangzhou, Zhejiang, China.
- Batch documentation. Per-batch COA (viscosity with full test conditions, pH, moisture, appearance), TDS (mixing ratio, open time, shelf life), MSDS. We support COA/TDS/MSDS and export files.
- Sample flow before bulk. A test sample on your target wallpaper type, applied vertically to check initial tack and slip, before you commit to a container.
- Standard packing. 20 kg kraft paper bag with inner PE liner (moisture protection for container shipping). Confirm the liner, batch label, and shipping marks.
- OEM capability. If you plan a private label: pack sizes (200 g / 300 g / 500 g / 1 kg / custom), pouch/label/carton customization, multilingual instructions, barcode.
- Delivery route. Can the factory ship to your own forwarder's warehouse in China (FOB/EXW)? This is the common arrangement for importers who consolidate.
- Communication & quote discipline. Whether they will state price, MOQ, and lead time in writing, for your specific project, rather than vague ranges.
- No overpromising. A supplier who claims unverified certifications or guarantees should be treated with more caution, not less.
4. Coverage and mixing: keep the reference numbers honest
Coverage depends on the wallpaper type, wall condition, water ratio, and application method. A responsible supplier gives you a reference value and tells you what changes it. Example from our own pages: a 200 g pack mixes to approximately 25–30 m² of standard non-woven wallpaper under normal conditions — less on heavy vinyl or uneven, absorbent walls. Plan a small test patch before you calculate your container buy.
Mixing process we recommend on our TDS: slowly pour the powder into clean cold water while stirring, stir until the powder is lump-free, then let it rest per the resting time stated in the TDS of your model, stir once more before use.
5. Common sourcing mistakes
- Comparing viscosity numbers without matching test conditions (see Section 2).
- Buying on price alone — then discovering a missing COA, a leaky liner, or a brand clash at the destination.
- Skipping the vertical sample test on your actual wallpaper.
- Assuming one model fits every market — paper-based wallpaper, non-woven, and vinyl need different handling.
6. What to include in your RFQ
To get a precise commercial offer — and to compare suppliers fairly — send the factory this list:
- Target market and channel (wholesale / repacking / private-label brand).
- Estimated annual volume and first order size.
- Packing format: 20 kg bulk, OEM small packs (200 g / 300 g / 500 g / 1 kg), or both.
- Model preference or "recommend for my wallpaper mix."
- Currency, destination port, or your China forwarder's warehouse address.
- Documents needed: COA / TDS / MSDS, packing list, pre-shipment photos.
Price and MOQ: we quote per project. Send us your volumes and packing format via the contact page or WhatsApp and we will respond with a written quotation for your specific case — that keeps the numbers real for both sides.
7. Why factory-direct 20 kg supply fits certain buyers
Factory-direct bulk makes sense when you have a repacking line, a distribution warehouse, or a private-label brand of your own. You take the starch-based raw powder, repack it under your brand, and keep the margin. It is not the right model for a one-off retail order — for that, a ready-made local product is simpler. Decide your model before you approach any factory.
FAQ
What is the difference between wallpaper adhesive powder and ready-mixed paste?
Powder is dry starch-based material you mix with cold water before use (typically 1:25 or 1:30); it is lighter to ship in bulk and has a longer shelf life. Ready-mixed paste is pre-made and convenient for retail, but costs more to transport and stores for less time.
What is the standard packing for bulk wallpaper glue powder?
The common industrial format is a 20 kg kraft paper bag with an inner PE liner, which protects the powder from moisture during container shipping. KARN ships this way and supports clear batch labels and English/bilingual shipping marks.
What is a typical mixing ratio?
About 1:25 to 1:30 (powder to water by weight): 1:25 gives a thicker paste suitable for heavier wallpaper; 1:30 is thinner for standard non-woven. Confirm the exact ratio on the TDS for your model.
How much area does a 200 g pack cover?
As a reference, about 25–30 m² of standard non-woven wallpaper under normal conditions. Actual coverage depends on wallpaper type, wall surface, water ratio, and application method — always run a small test patch.
What documents should a wallpaper glue factory provide?
Per-batch COA (with viscosity test conditions), TDS, MSDS, packing list, and export documents. KARN supports COA/TDS/MSDS and export files, and can arrange pre-shipment photos.
Can I get samples before a bulk order?
Yes. A test sample on your target wallpaper, applied vertically to check tack and slip, is the standard first step. Contact us for sample arrangements and the current process.
Do you support OEM / private-label packing?
Yes. Pack sizes from 200 g / 300 g / 500 g / 1 kg to custom sizes, with pouch, label, carton, barcode, and multilingual instructions. Sample approval happens before bulk production.
Next Step
Shortlist two or three factories, send each the same RFQ list from Section 6, and compare the answers side by side. To test this framework against our own data, contact us for a written quotation with your market, pack sizes and monthly volume.