01
Saponified soap penetrates the substrate
Shellac and natural-resin are saponified by potash into water-soluble soap form. Dilute 1:1 with water; the primer flows into the pore network rather than sitting on the surface.
DEEP SEALER · ART. 620
The canvas under the wall paint.
LEINOS 620 Deep Sealer — water-based deep-penetrating primer for highly or variably absorbent interior wall substrates. Saponified shellac and natural-resin soap flow into the pore network; carnauba and beeswax bind substrate dust and even the absorbency canvas. Solvent-free, plasticiser-free. VOC less than 1 g/l. Made in Germany by Reincke Naturfarben since 1985.
Water-based deep penetratorEvens absorbency canvasVOC <1 g/l · EU Cat. aSolvent-free · plasticiser-free
Mechanism & Use
How 620 Deep Sealer works.
Substrate absorbency varies square metre by square metre — chalking lime, patched repair zones, bonded ingrain wallpaper, gypsum board partition walls. Variable absorbency is the silent failure mode behind patchy topcoat finish. 620 brings the substrate to a single, even, controlled absorbency: saponified shellac and natural-resin soap flow into the pore network, carnauba and beeswax cure as the binding film, and the topcoat that follows lays down at uniform thickness and reads as a single colour register.
02
Wax phase evens the absorbency canvas
Carnauba and beeswax cure inside the pore network as the water phase evaporates — bind substrate dust, present an even matt absorbency face for the topcoat.
03
One primer, multiple LEINOS topcoats
Covers the natural-resin emulsion line (660 / 650), clay paint (655), casein (640), plaster effect (680). For lime paint (665), use 622 Mineral Plaster Primer instead.
04
Water-based, solvent-free, very low VOC
Plasticiser-free; VOC less than 1 g/l (EU Cat. a). Mild BIT preservative for can-stability — the cured film on the wall contains no biocide and no solvent.
Where It Lives
Where 620 Lives
Gypsum-board partition walls (drywall) in contemporary apartment fit-outs
Most common contractor case in Indian apartment shell fit-outs — gypsum board partition walls are highly absorbent and absorbency varies from board to board. One coat of 620 diluted 1:1 with water evens the canvas; the natural-resin emulsion topcoat (660) or interior white topcoat (650) that follows lays down at uniform thickness across the whole wall. Per leinos.de: 620 on plasterboard before further treatment with LEINOS wall paints.
Chalking lime plaster + very porous cement plaster + patched repair zones
Older lime plaster walls that chalk powder under a fingertip touch, very porous freshly cured cement plaster, mixed-substrate zones where wall has been repaired in patches — all read as highly variable absorbency to a topcoat. 620 saponified soap chemistry penetrates into the pore network, the wax phase binds the chalking dust into the wall, the absorbency canvas evens out. The topcoat sits true.
Bonded ingrain wallpaper feature walls (Raufaser) over absorbent substrate
Common in Indian apartment fit-outs as a textured feature-wall solution. Bonded ingrain wallpaper firmly adhered to a mineral substrate is a TDS-listed substrate for 620 — the primer flows through the wallpaper into the substrate beneath and binds both surfaces into a single uniform absorbency canvas. The clay paint (655) or natural-resin emulsion (660) topcoat that follows reads as a single matt surface with the wallpaper texture visible beneath. Vinyl or plastic-coated wallpaper is NOT a suitable substrate.
OSB-board feature walls in contemporary fit-outs
Contemporary fit-outs that mix exposed OSB structural board with painted finished walls — the OSB-board surface takes 620 + a mineral topcoat (655 clay or 660 natural-resin emulsion) and reads as a unified matt mineral surface across the substrate mix. TDS-supported via the 655 + 620 systemChain (locked pilot 9). The OSB substrate must be firmly adhering, dust-free, and sealed at the edges.
Old, firmly-adhering matt emulsion walls — repaint over an existing finish
Per leinos.de: 620 over “old, firmly adhering coats of wall paint.” Common Indian repaint scenario — an apartment with an existing matt emulsion or mineral paint that is sound, matt-finish (not glossy), firmly adhering, and not flaking. Clean thoroughly + dust-free + light mechanical key if any residual sheen, then 620 evens the absorbency face and the new topcoat lays down at uniform thickness. Glossy emulsion or intact vinyl wallpaper is NOT suitable — strip back to absorbent substrate or mechanically key first.
Mixed-substrate apartment shells — same primer across the entire wall plan
Real Indian apartment shells carry mixed substrates across a single floor plan: gypsum-board partition walls in some rooms, lime-plastered structural walls in others, bonded ingrain wallpaper on a feature wall, patched repair zones around electrical work or window frames. 620 spans all of these in one primer spec line — the contractor primes the whole shell to a single uniform absorbency canvas before the topcoat colour goes on. One primer, one workflow, one spec line.
Compliance · Natural Ingredients · EU
Documented natural chemistry. Cat. a VOC. Solvent-free, plasticiser-free.
Three anchors that let architects and contractors specify 620 alongside any LEINOS natural-chemistry topcoat without the acrylic-primer disclosure.
EU Compliance
VOC <1 g/l
EU limit 30 g/l · Cat. a interior matt walls (water-borne) · Directive 2004/42/EC.
Institutional Pledge
InVeNa Member
Reincke Naturfarben — full-ingredient-disclosure pledge for natural building products.
Origin
Made in Germany
Manufactured by Reincke Naturfarben, Lower Saxony, est. 1985.
The TDS is downloadable below — substrate range, dilution canon, drying time, application temperature, pack coverage. The Safety Data Sheet (SDS) is supplied on request from LEINOS India for the full hazard register and the trace-functional-additive disclosure. Where you need a written specification packet — full ingredient declaration, VOC compliance letter for an architect’s submittal, substrate-compatibility statement for a mixed-substrate apartment shell, or a primer-and-topcoat system brief tied to a project topcoat colour register — it is available to architects and contractors on request. Use Get Expert Advice above.
Read The Full TDSStep by Step
How to Apply
Substrate inspection — the wall must be dry, clean, free of dust and grease (leinos.de). Test absorbency: a damp brush stroke should darken the surface evenly. Mineral plasters cured 2-3 weeks. Gypsum board, bonded ingrain wallpaper, and OSB-board: firmly adhering, dust-free. For repaints, the existing coat must be sound, matt-finish, firmly adhering, not flaking — light mechanical key if any residual sheen.
Dilute 1:1 with water before use — TDS explicit. Pour 620 into a clean painter’s bucket, add an equal volume of cold tap water, stir thoroughly until the liquid reads uniform translucent off-white. Do not apply 620 undiluted — the chemistry depends on water-carrier penetration into the substrate.
Apply by brushing, rolling, or spraying. Ambient and substrate temperature above 15 °C (TDS minimum). Work in all directions so the saponified soap penetrates the pore network uniformly; on roller, finish with light cross-strokes. The primer goes on as a transparent wash and cures invisible — the test is the dried absorbency face, not the wet appearance.
One coat is typically sufficient. Touch-dry 2-4 hours at normal room temperature. CRITICAL per leinos.de canon: the substrate must remain MODERATELY ABSORBENT after priming — do not over-prime. The primer evens absorbency variability; the topcoat needs an absorbent face to bond. Optional second light coat only for very highly absorbent or chalking substrates.
Topcoat-ready check + cleaning. Lightly damp-brush an inconspicuous area — moisture should darken evenly across the wall, not patchier in any zone. Once uniform, the wall is ready for the topcoat (660, 650, 655, 640, 680 per project spec). Clean tools immediately with cold tap water — saponified soap and wax rinse clean before cure sets in. Store closed pail dry, cool, frost-protected.
Application Conditions
- Substrate must be dry, clean, free of dust and grease (leinos.de canon).
- Mineral plasters (lime, cement) must be at least 2 to 3 weeks cured before priming.
- Ambient and substrate temperature above 15 °C (TDS minimum).
- Dilute 1:1 with water before use — never apply 620 undiluted.
- Ensure good ventilation during application and the first 4 hours of drying.
Coats & Recoating
- 1 coat is typically sufficient for sound absorbent substrates.
- Optional 2nd light coat for very highly absorbent or chalking substrates — apply once the first coat is touch-dry.
- Critical caveat per leinos.de canon: the substrate must remain MODERATELY ABSORBENT after priming for the topcoat to bond — do not over-prime.
- Touch-dry approximately 2 to 4 hours at normal room temperature. Topcoat-ready after the cure window.
Cleaning & Storage
- Clean tools immediately after use with cold tap water — saponified soap and wax rinse clean before the cure sets in.
- Store in a dry and cool place, protect from freezing. Shelf life in closed packaging is at least 2 years.
First time with Deep Sealer? Our technical team runs complimentary on-site walkthroughs for contractors — full application protocol, start to finish.
System & Substrates
The deep-penetrating primer for absorbent interior wall substrates.
One primer spec line covers the LEINOS apartment fit-out range — natural-resin emulsion (660 architect-line, 650 contractor-line), clay paint (655 premium decorative), plus TDS-listed casein (640) and plaster effect (680). For lime paint (665), specify 622 Mineral Plaster Primer instead. Dilute 1:1 with water; the substrate must remain moderately absorbent after priming for the topcoat to bond (leinos.de canon).
The Coating System
Primer plus topcoat — the full chain.
Primer620Deep Sealer
Topcoat Options
Choose the finish character; the primer underneath stays the same.
Clay Paint655Clay Paint
Substrate Fit
620 works on — and what it doesn’t.
Suitable
Recommended substrates
- Plasterboard / gypsum board / drywall
- Neutral plasters (lime, cement, gypsum — cured 2-3 weeks)
- Porous stone (sandstone, terracotta wall tile, mineral interior face brick)
- Old, firmly-adhering coats of matt wall paint
- Chalking lime plaster
- Patched repair zones in mixed-substrate walls
- Bonded ingrain wallpaper (Raufaser, firmly adhered)
- OSB-board feature walls (firmly adhering, dust-free, sealed-edge)
Honest Limits
Where to use a different product
- Wood substrates of any kind (interior wood floors, furniture, doors, ceilings, panels). Use the LEINOS wood-finish primer line — e.g. LEINOS 150 Impregnation Primer
- Lime paint and silicate paint topcoats (different chemistry family). Use LEINOS 622 Mineral Plaster Primer
- Non-absorbent or sealed surfaces (glazed ceramic tile, glossy lacquer, intact vinyl wallpaper, polymer-sealed floors). 620 chemistry depends on substrate absorbency — strip back to absorbent mineral substrate or mechanically key first.
- Exterior applications (interior wall + ceiling only per TDS). Use the LEINOS exterior facade primer + paint line for outdoor walls.
- Permanently wet or submerged areas (bathroom shower stalls, basement walls below the waterline, swimming-pool surrounds). For active-mould-risk humid bathrooms, specify LEINOS 665 Lime Paint
Use With Care
Working safely with 620
- Contains 1,2-benzisothiazol-3(2H)-one (BIT) — may cause allergic reactions in sensitised individuals. Standard painter’s gloves and eyewear during application handle the wet-pail exposure register correctly.
- Store away from children. Keep the pail closed and out of reach when not actively in use.
- Avoid contact with eyes, skin, and clothing. Wash any splashes with plenty of water and soap immediately. If skin irritation or rash occurs, get medical attention.
- Ensure adequate ventilation during application and the first 4 hours of drying — open windows and run room fans on low if the room has no cross-ventilation.
- Avoid release to the environment. Do not pour wet-primer residues to drains, soil, or watercourses. Dispose of dried product residues with household waste; dispose of liquid residues per local hazardous-waste regulations. Disposal code: EAK/EWC 08 01 12. Safety Data Sheet (SDS) is supplied on request from LEINOS India for the full hazard register.
Coverage & Pack Sizes
One coat per wall · 2 691 sq ft per 10 L pack.
Coverage varies with substrate absorbency. Chalking lime plaster and stipple-finished gypsum consume more than smooth skim plaster. TDS-published coverage assumes 1:1 dilution with water — never apply 620 undiluted. One coat is the canon for sound absorbent substrates per leinos.de; optional second coat for very highly absorbent or chalking substrates.
1L
Covers
110–180 sq ft
1 coat, absorbent mineral
Best For
Touch-up, small repair zone, single small bedroom or bath wall.
2.5L
Covers
275–450 sq ft
1 coat, absorbent mineral
Best For
Single full room, feature wall section, or small apartment project.
10L
Covers
1100–1800 sq ft
1 coat, absorbent mineral
Best For
Full apartment shell-fit-out, contractor project, multi-room development.
sq ft
Enter your floor area to see how many litres — and the most efficient pack mix — you’ll need for 1 coat.
Documented Applications
See this product in real projects
Documented mineral surface projects. Captions show which LEINOS finish was used.
Full Declaration
Composition
Every ingredient declared on the label. The Trust Hub explains what each one does and the standards behind it.
Saponified Shellac + Natural-Resin Soap
Shellac (lac-beetle natural resin) and natural rosin-derived resin converted to soap form by potash (potassium carbonate). Water-soluble at point of application — flows into the pore network of absorbent substrates. As the water phase evaporates, the soap precipitates back into film-forming components held inside the cured wax phase. The depth of penetration is what makes the “deep sealer” name accurate.
Carnauba + Beeswax (Wax Binder Phase)
Carnauba wax (palm-derived, highest melting point of natural waxes) and beeswax (apiculture natural wax). The wax phase cures inside the substrate pore network as the water phase evaporates — binds substrate dust into the cured film, holds the saponified resin in place, and presents the even matt absorbency face that the topcoat sees. Same wax canon as LEINOS oil-wax topcoats (290 Hardwax Oil) — natural-materials chemistry, not synthetic-polymer chemistry.
Cellulose Thickener + Potash (Rheology + Saponification)
Cellulose thickener holds the saponified suspension stable in the wet pail and at point of application. Potash (potassium carbonate) is the saponifying agent — it converts the shellac and natural resin into soap form so they dissolve in water and flow into the substrate. Water is the carrier — evaporates after application, the cured film contains no water and no solvent.
Mild Preservative · Benzisothiazolinone (Tier 2)
1,2-benzisothiazol-3(2H)-one (BIT) at preservative-level concentration keeps the wet pail stable through the 2-year shelf life. TDS verbatim disclosure — may cause allergic reactions in sensitised individuals (standard wet-paint allergen register). The cured primer film on the wall contains no biocide and no solvent; the preservative role applies only to the wet pail in storage. SDS supplied on request from LEINOS India for the full hazard register.
Got Questions?
Frequently Asked
Quick answers on formulation, application and Indian-climate suitability. Pulled from our full FAQ and TDS library.
- It depends on the condition. Sound, non-chalking, well-bonded dispersion coatings can usually be primed with LEINOS Mineral Plaster Primer 622 first — the primer creates a uniform mineral base for the topcoat. Flaking, chalking, or oil-based finishes must be fully removed back to a sound mineral substrate.
- Yes. LEINOS mineral wall paints are fully breathable (vapour-permeable), allowing moisture to pass through the wall structure naturally.
- The surface must be clean, dry, and structurally sound. New plaster must be fully cured (typically 4 weeks). Prime with the recommended mineral primer.
- The “deep” is literal — saponified shellac and natural-resin soap is water-soluble at point of application and flows into the pore network rather than sitting on the surface as a film. The wax phase (carnauba + beeswax) cures inside the pore network: binds substrate dust, holds the saponified resin, presents the even matt absorbency face the topcoat sees. The cured primer is invisible — the test is the dried absorbency face, not a visible film.
- Depends on the topcoat. 620 is for natural-resin emulsion (660 / 650), clay paint (655), casein (640), plaster effect (680). 622 is a silicate-chemistry primer for lime paint (665) and the silicate topcoat family. Not interchangeable — mixing the wrong primer with the wrong topcoat causes adhesion failure and uneven absorbency.
- Yes — TDS explicit. Dilute 1:1 with clean cold tap water. The saponified soap chemistry depends on water-carrier penetration; applying 620 undiluted defeats the deep-penetration mechanism (the soap sits on the surface instead of flowing into the pore network). Stir thoroughly until the liquid reads uniform translucent off-white.
- One coat is typically sufficient for sound absorbent substrates. For very highly absorbent or chalking substrates (e.g. very porous freshly cured cement, OSB-board feature walls) a second light coat may be applied once the first is touch-dry. Critical caveat per leinos.de canon: the substrate must remain MODERATELY ABSORBENT after priming for the topcoat to bond — do not over-prime.
- 15 °C ambient and substrate — TDS minimum, higher than the 10 °C minimum of most LEINOS topcoats because saponified soap chemistry cures slower at low temperature. In Indian climate this is rarely a constraint. If the site is below 15 °C, run a fan heater to bring the room to working temperature before priming.
- Yes — per leinos.de, 620 is suitable over “old, firmly adhering coats of wall paint.” The existing coat must be sound, matt-finish (not glossy), firmly adhering, free of grease or wax. Clean + dust-free + light mechanical key if any residual sheen, then 620 evens the absorbency face. Glossy emulsion, intact vinyl wallpaper, and polymer-sealed walls are NOT suitable — strip back or mechanically key first.
- 620 is water-based, solvent-free, plasticiser-free, low-odour. VOC less than 1 g/l (EU Cat. a). The composition contains 1,2-benzisothiazol-3(2H)-one (BIT) as a wet-paint can-stability preservative — standard across the natural-paint industry. BIT may cause allergic reactions in sensitised individuals; painter’s gloves and eyewear handle the wet-pail exposure register. The CURED film on the wall contains no biocide and no solvent. SDS supplied on request.
For Architects & Specifiers
Downloads
Technical and safety documents — citable in project specifications.
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Written by the LEINOS India technical team, in collaboration with Reincke Naturfarben R&D, Lower Saxony.
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