Wallpaper adhesive powder for heavy vinyl and non-woven wallpaper

Choose by substrate before you compare models. Heavy vinyl is thick, heavy and low-breathability, so the paste has to hold the seam while it is still wet. Non-woven is usually pasted on the wall and needs an even film that stays open. Paper and wall cloth sit in between. This page helps procurement teams evaluating wallpaper adhesive for heavy vinyl.

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Match the paste to the substrate, not to the label

A bag that says "for heavy wallpaper" is a marketing line, not a specification. The substrate tells you which behaviour matters: how long the strip stays workable, whether the paste has to carry weight before it dries, and how much moisture the facing lets through.
Heavy vinyl: a PVC or similar facing on paper or non-woven backing. The roll is heavy and releases little moisture, so it keeps pulling on the seam while the paste is wet. Check seam hold and how long the installer can still slide the strip into position.
Non-woven: dimensionally stable backing, commonly pasted on the wall instead of on the strip. The film has to spread evenly, stay open for a full drop, and not strike through a thin facing.
Paper: swells when it takes up water. Paste on the strip, book the drop, and keep the mix identical from drop to drop so the seams close the same way across the room.
Wall cloth (textile): the heaviest facing and the least forgiving of a dry edge. Confirm the wall primer and the paste film with the installer before the first full drop.

What the published model data can and cannot tell you

KARN publishes nominal viscosity for the finished grades under one fixed set of conditions: 5% solution, NDJ-8 viscometer, No. 4 rotor, 6 rpm, quoted with a ±10% tolerance. Compare figures only inside that set, and treat them as a description of the powder, not as a promise about your wall.
K6 carries a published 38,000 ±10% mPa·s. For 999 and 999+, the current figure for the model is published in the TDS that arrives with the quotation, so read that document instead of a number copied from a brochure or from another supplier.
K6 · Ordinary grade · Tapioca modified starch · 38,000 ±10% mPa·s (5% solution; NDJ-8; No. 4 rotor; 6 rpm)
999 · Main export model · Potato modified starch · Viscosity per model TDS
999+ · Anti-mold grade · Potato modified starch · Viscosity per model TDS
KN-999 · Raw-material base powder · Modified starch base · Measured on a different instrument, not comparable with the finished grades
KN-999 is a raw material offered for repacking, not a fourth finished grade. Its figure comes from a different instrument and sample preparation, so ranking it against K6, 999 and 999+ is meaningless.

Mixing ratio and the coverage reference

The published mixing guidance is 1:25 or 1:30 powder to water. Both ratios are used in the field; which one fits depends on the roll weight, how absorbent the wall is and how the installer works. Weigh the powder and the water, note the water temperature, and keep the same rest time before use, otherwise two drops from the same bag behave differently.
A 200g pack is published with a reference coverage of about 25–30 m². That is a planning figure, not a guarantee: wall texture, primer, paste thickness and waste all move it. Do not scale the 200g number up and present the result as published data for a 20kg bag.

A trial that still means something on a bulk order

Pick two models, not four, and mix both at the ratio you intend to print on the pack.
Record powder weight, water weight, water temperature, mixing time and rest time.
Spread both pastes on the same wall with the same tool, then hang the same wallpaper you actually sell.
Write down open time, how far the strip slides, seam tightness, and the dry result after a full drying period.
Keep a roll offcut and the mix record with the samples, so the bulk batch can be checked against the mix that passed.

Packaging and what is confirmed per order

Bulk supply is 20kg per bag in a kraft paper bag with a PE liner. Pallets, container loading, shipping marks and labels are confirmed per order rather than assumed from a catalogue. OEM small packs run from 200g to 1kg with the bag format agreed for the project.
Price, MOQ, lead time and freight depend on the model, the pack format and the route, so they are quoted against your inquiry instead of being published as fixed numbers.

Frequently asked questions

Do heavy vinyl and non-woven wallpaper need different adhesive powder?

Not by default. KARN supplies one dry powder family, and the model plus the mixing ratio decide the working behaviour. The substrate decides what you test: seam hold and open time on heavy vinyl, film evenness and no strike-through on non-woven.

Is K6 enough for a heavy vinyl roll?

K6 is the ordinary grade on tapioca modified starch. Whether it is enough depends on the roll weight, the wall and the installer, which is exactly what the trial is for. The TDS gives the reference viscosity, not the answer for your wall.

Does a higher viscosity number mean a stronger bond?

No. The figure describes paste thickness under fixed laboratory conditions. Bond performance on a wall depends on the wallpaper, the substrate, the primer, the mixing ratio and the application.

How much wall does a 200g pack cover?

About 25–30 m² is the published reference for a 200g pack. It is a planning figure, not a guarantee: wall texture, primer, paste thickness and waste all change the real number.

Can you confirm the mixing ratio for my wall?

1:25 or 1:30 powder to water is the published guidance. Which one fits depends on the roll, the wall absorption and the installer, so it is settled in the trial and then printed on the pack you order.