Once your Color Skim walls are troweled, there is one more decision that shapes the final look: whether to seal, and with what. Sealer is optional with Color Skim. Some people love the soft, velvety matte of unsealed lime plaster. Others want a little more glow. This guide explains your three options (Gloss, Low Gloss or no sealer), how each affects the look, and when to apply.
The quick answer
- No sealer: the most matte, natural look. A good choice for low-touch walls.
- Low Gloss sealer: adds a soft sheen while keeping the look understated.
- Gloss sealer: gives more sheen than Low Gloss, for a richer, more reflective surface.
Both Lime Plaster Sealer options, Gloss and Low Gloss, add sheen. If you want the wall to stay completely matte, the answer is not to seal.
Sheen starts with your trowel
Before you think about sealer, remember that technique already sets the baseline:
- Unburnished: leaving the final coat as troweled gives a soft matte finish. This is the easiest route for DIY.
- Burnished: once the final coat is fully dry, working the trowel over the surface increases sheen and depth.
Sealer sits on top of whichever finish you created. An unburnished wall with Low Gloss will look different from a burnished wall with Low Gloss, so try your combination on a sample board first.
Option 1: No sealer
Unsealed Color Skim shows lime plaster at its most natural: soft, chalky-matte and velvety, with the color movement fully visible and no added reflection. It also keeps the plaster at its most breathable. Sealing, with either Gloss or Low Gloss, reduces breathability.
Consider it for:
- Low-touch walls: above head height, ceilings, formal living and dining rooms, bedrooms, and feature walls that aren't brushed against
- Anyone who wants the most matte, mineral look
- Lighter shades like 121 Chalk or 124 Intonaco, where a matte finish gives a calm, gallery feel
If you aren't sure, you can leave a wall unsealed, live with it, and decide later. Sealer can be applied once the plaster has cured.
Option 2: Low Gloss sealer
Low Gloss adds a soft sheen. It deepens the color slightly and gives the surface a gentle glow, without the reflectiveness of a full gloss.
Consider it for:
- Rooms where you want a finished look that still feels understated
- Mid-tone neutrals and earth tones like 126 Trass, 125 Tivoli or 154 Shale
- Pairing with a lightly burnished surface for subtle depth
Option 3: Gloss sealer
Gloss gives more sheen than Low Gloss. It gives the plaster a richer, more reflective surface that catches light and highlights trowel movement. This is closer to the polished look many people associate with Venetian plaster.
Consider it for:
- Statement walls, powder rooms and dining rooms where you want drama
- Deep accents like 131 Klinker, 142 Galbe or 135 Tephra, where sheen adds richness
- Burnished walls where you want to push the depth further
Comparison at a glance
| No sealer | Low Gloss | Gloss | |
|---|---|---|---|
| Sheen | Matte (unless burnished) | Soft sheen | More sheen than Low Gloss |
| Look | Velvety, natural, mineral | Understated glow | Rich, reflective |
| Good for | Low-touch walls, matte lovers | Most rooms wanting a subtle finish | Feature walls, dramatic rooms |
| Coverage | None | About 300 sq ft per gallon (2 coats) | About 300 sq ft per gallon (2 coats) |
| Breathability | Most breathable | Reduced by sealing | Reduced by sealing |
Choosing by room
There is no single right answer, but these starting points help:
- Bedrooms: unsealed or Low Gloss keeps the room calm and soft. Matte surfaces feel restful, especially in lighter shades like 145 Vestige or 146 Stria.
- Living rooms: Low Gloss is a balanced choice for main walls. Consider Gloss on a single feature wall for contrast.
- Dining rooms: evening light and candles flatter sheen. Low Gloss or Gloss both work, depending on how dramatic you want the room.
- Entries and hallways: these walls are often brushed by hands, bags and furniture, so decide whether you prefer a matte look or a sealed finish, and test on a sample board.
- Ceilings and high walls: these are rarely touched, so they are an easy place to skip sealer and enjoy the most matte look.
- Powder rooms: a small room is a great place to try a deep shade with Gloss for a jewel-box effect.
What sealer does to color
Adding sheen changes how you perceive color, not the color itself. A sealed surface reflects more light, so expect:
- Colors that read a little richer and deeper, especially mid-tones and deep accents
- More visible trowel movement, because reflections pick out the strokes
- A surface that changes more with viewing angle and light direction
If you fell in love with a color as an unsealed chip, test it sealed before committing. The difference can be noticeable, particularly with Gloss.
Common mistakes to avoid
- Sealing too soon. Give the plaster about two weeks (7 days to 3 weeks), longer in cool or humid conditions.
- Expecting sealer to stay matte. Both Gloss and Low Gloss add sheen. Skip sealer for a matte finish.
- Using the wrong product. Use water-based sealers only on Color Skim.
- Skipping the test. Sheen is personal. A three-section sample board shows you all three options in your own light.
- Mixing finishes on one wall. Choose one finish per wall (or per room) so the surface reads consistently.
When to seal
Lime plaster needs time to cure before sealing:
- Plan to seal about two weeks after your final coat.
- The usual window is 7 days to 3 weeks. In poor drying conditions (cool or humid rooms), go closer to 3 weeks.
- Longer curing is ideal if your timeline allows.
- Use water-based sealers only.
- For wax, soap or oil finishes instead of sealer, wait at least 48 hours (1 week recommended).
Keep the room within the recommended conditions while the plaster cures: 55–85°F (13–29°C), ideally 50–75% relative humidity.
How to apply sealer
- Use a microfiber roller, or a paintbrush for small projects.
- Two coats is typical.
- Apply evenly across the whole wall, so the sheen reads consistently.
How much sealer do you need?
Lime Plaster Sealer covers about 300 sq ft per gallon for the typical two coats (both coats together). For comparison, a Color Skim gallon kit covers about 50–75 sq ft in two coats, so one gallon of sealer covers the area of several plaster kits. Measure your wall area and divide by 300 to estimate gallons for a two-coat seal. Sample jars are available if you want to test on a board first.
Test before you commit
The best way to choose is to see all three side by side:
- Make a sample board (or use an inconspicuous wall area) with your chosen Color Skim color and technique.
- Let it cure as you would the real wall.
- Divide it into three sections: leave one unsealed, seal one with Low Gloss and one with Gloss.
- View it in your room's light at different times of day.
Frequently asked questions
Do I have to seal Color Skim?
No. Sealer is optional. On low-touch walls you can skip it to keep a matte look and full breathability.
Will sealer keep my walls matte?
No. Both Gloss and Low Gloss add sheen. For a fully matte finish, leave the wall unsealed and unburnished.
Can I burnish and seal?
Yes. Burnishing raises sheen first, and sealer adds more on top. Test the combination on a sample board.
How soon can I seal?
About two weeks after the final coat is typical (7 days to 3 weeks), closer to 3 weeks in poor drying conditions.
Shop Lime Plaster Sealer (Gloss or Low Gloss) → · Browse Color Skim colors → · Read How to Apply Lime Plaster Over Drywall
