Spectrophotometer

Bassoon room patch - light green

Living room wall patch - red

This weekend, I touched up the wall paint in the areas where I patched the holes cut by the electricians during the house rewiring.  My house's previous owner told me that she researched colors that would have been used in a Craftsman-style bungalow in the 1920s and had the colors she picked out custom mixed.  She chose a deep red for the living room walls.  I don't think I would ever have been bold enough to paint it that color myself, but I actually really like it.

Custom-mixed colors can be problematic when you need to match them for touch-up painting.  It used to be very difficult.  However, these days, paint stores can match paint color samples electronically using a spectrophotometer.  It shines a white light at the paint sample and measures the wavelengths of the reflected light.  The detector has a bunch of filters that let through only light of a very specific wavelength.  It tries all the different filters and measures the amount of light reflected from the paint sample that is able to pass through each.  This way, the computer knows how much of each wavelength makes up the color.  The computer then calculates the mix of paint pigments that would replicate the color.

I didn't get to use a spectrophotometer for this project, though.  Maybe I'll do it just for fun some day.  For this project, conveniently, I found all the right paint colors in the garage, left by the previous owner.  Some of the paint was still good, but the red living room paint was all chunky and gross.  I just took it to Lowes, where she bought it, and they were able to replicate the custom color using the numbers from the sticker on the can.  Their numbering scheme presumably has to do with the relative amounts of each pigment, as well as the type of base paint and the shininess (eggshell, satin, etc.).

Bedroom patch - darker green

Kitchen patch - yellow

My wall patching is officially complete, and I would say it was highly successful.  The patches blend right in.  You can still see them if the light is right because the texture doesn't match the rest of the wall, but you wouldn't notice them if you weren't looking for them.

(Note that the colors in the photos here aren't very true to the actual colors on the wall.  My phone doesn't take very good pictures, but you get the idea.)