Polished plaster touch up

title image

Performing a touch up on a polished plaster wall, can be a huge challenge.  If the area is small enough, it can be masked using this technique below.  Previously, we’ve discussed the “touch-up” subject before; once on touching up a hole on a wall and more recently, how to touch up a cracked strie.

Here’s our main foreman, Jon Smith with his tutorial of how it’s done at Grand Illusion Decorative Painting, Inc.

Jon: “Where’s the touch-up?”

wheres the touch up

This is the damaged area on the polished plaster.  It’s a 3-D divot in the wall from the movers, we’re guessing.

damaged area

Here the hole is taped off (being careful to leave a 1/16 inch of wall exposed)  and ready to fill.

tape up

I mixed a combination of 80% ez-45 compound and 20% plaster of Paris.

mix plaster

Using a palette knife (best because it is a flexible blade), I generously fill and smooth.

apply plaster

Use a hair dryer to speed up the dry process.   Still, make sure the patch is completely dry to the core and not just the surface.


Sand with soft 320 pad, softly and with gradual pressure.

repeat if necessary

Wipe away the area with a damp rage and continue to sand until you can see the original taping.

sand area

Remove the tape and you will be left with a very small lip of plaster.

remove tape

Sand with a 800-1000 grit pad to remove the lip. Being careful not to over sand or damage the surrounding area.   Feel with you hand to make sure you are 100% smooth with no lip or dimple.

remove tape

The plaster has now been sanded smooth with the surface.

sand carefully

I used some thinned down shellac. This seals the plaster so the water based paint will not reactive the plaster and cause damage to the nice, smooth touch-up I created with the plaster.


Apply the shellac with the correct brush size for the job.


Make sure you carefully apply the shellac on just the area that’s damaged.

after shellac

Side view of the shellac over the touch up

after shellac

After the shellac dries use a used 800-1000 grit sand pad to sand down any brush strokes that may have been cause by brushing on the shellac.

sand again

The colors I used to match the color.

color palette

I add 5-10% of varnish for the appropriate sheen to my water that’s in my pallette cup. Reason for this.. When you dry down a color and then apply a varnish over the top this can sometime cause the color to change and you have to start all over again…. So by adding a small % of varnish to your water helps you see the true color and close to the right sheen once it dries.


It’s important to work opaque with your color but keeping your paint thinned down , once again so you get the touch up area as smooth as possible so it blends in with the rest of the plaster.


Shows in progress. I mix on my palette to the overall color of the wall and paint out the area. Dry it down and then take that color and slowly adjust it by adding some darker colors to create some darker values to mimic the darker areas in the plaster caused from burnishing the plaster.
It’s important to work within the touch up area.  If you don’t, your touch up area will grow and grow.

This is a difficult step of the process, but try to get the color right the first time and avoid painting the area over and over again.


Touching up adjusting the color slowly as I work and constantly drying it down.


You can see the touchup on left hand side 1/3 of the way in just under halfway.


Where’s the touch up???



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