Painting on Colored Surfaces
In a perfect world we could paint on any color surface and the glow in the dark paint would glow as bright and for as long on all surfaces. The reality is far from ideal. The glow in the dark paint paint emits light in all directions. When painted on a white surface some of that emitted light bounces off the white surface and towards the viewer. When the same paint is applied to a dark surface some of that emitted light is absorbed and not reflected. This causes two effects: The glow in the dark paint does not appear to glow as bright and does not glow for as long.
A common misconception is that the ceiling should be dark, like the sky at night. Customers that do this in advance of looking for a muralist are not helping and are often less satisfied with the results. I personally do not paint dark ceilings because of the problems associated with getting the paint to perform up to expectations.
There are a few remedies for this:
- Apply more glow in the dark paint by painting larger stars.
The downside to this is that the stars are likely to be visible during the day.
- Use UV light to charge the paint.
This always works but some customers do not want unsightly UV lights. It is also the only solution if you plan on painting effects such as the Milkway.
- Paint a light background before painting the stars.
Some people create a daytime sky mural first by painting clouds then apply the glow in the dark paint to the areas where the clouds are.
Example of Surface Colors
So you’ve probably read that glow in the dark paint is virtually invisible in the day. Well it’s not quite that simple. The smallest of stars will certainly be pretty invisible at more than a few feet. However, the larger stars will remain visible, certainly on darker ceilings. This might pose a problem for some customers so it would be advisable to demo a sample by painting a couple stars on the ceiling for them to evaluate before doing the entire ceiling and having an issue later.
Another thing to point out is that in a room with closed plantation shutters you might actually see the stars in the day. Our Super Green emits such a bright glow under UV that any light that enters the room on a sunny day can charge the glow in the dark paint so that they glow even with the shutters closed!
How long does the glow in the dark paint glow? This is a reasonable question and it really depends on many factors. Under ideal conditions green and aqua glow in the dark paint will glow all night.
Glow and After-Glow
There are two stages to the light emitted by glow in the dark paints: Glow and After-Glow. When someone talks about how long the glow in the dark paint glows they are often including the phase referred to as after-glow. The glow phase occurs when the light is first turned off and the paint is emitting at full strength. This is when the brightness of the paint is measured. The paint is losing brightness from the moment the light source is turned off. To be honest most of the paints will lose 50% of their initial brightness within the first minute. The after-glow phase is where the paint is still emitting light and is easily noticeable. It is the after-glow phase that separates good and bad glow in the dark paints.
Here’s the above color sample taken in the dark at various times. Note that the actual glow is better than represented here. These images fade quickly due to setting the camera to a short exposure. The intention is to show how the paint loses its glow and not to demonstrate how long the paint actually glows.
Taken immediately after a 10 minute UV charge.
Taken 30 minutes later.
Taken one hour later.
Taken one and a half hours later
You can clearly see how the glow in the dark paint works best on the lighter colors and how it fades the fastest on the darker colors.
Light and White Backgrounds and UV Light Source
Glow in the dark stars painted on a white or light background charged for 30 minutes by UV light will glow the brightest and longest. If you can install UV lights then you’ll get the best viewing.
The main constellation stars will almost certainly glow all night. The smallest stars will glow for many hours but probably less than 4. The Milky Way if painted with white will glow for an hour or less. If painted using the brightest green or aqua paints then it might have after-glow all night.
Dark Backgrounds and UV Light Source
Glow in the dark stars painted on dark backgrounds and charged for 30 minutes by UV light will glow very bright as soon as you turn off the lamp but will start to fade pretty quickly.
The main constellation stars will almost certainly glow for several hours. The smallest stars will glow for an hour or two. The Milky Way if painted with white will still only glow 30 minutes or less. If painted using the brightest green or aqua paints then it might have a weak after-glow for an hour or so.
Light and White Backgrounds and CFL Light Source
CFL and regular fluorescent lights are the next step down the ladder. A CFL bulb actually emits UV light and so does a pretty good job of charging the glow in the dark paint. Again light or white backgrounds rule and a charge time of 30 minutes is desirable.
The main constellation stars will almost certainly glow all night. The smallest stars will glow for many hours but probably less than 4. The Milky Way if painted with white will still only glow for an hour or less. If painted using the brightest green or aqua paints then it might have after-glow all night.
Dark Backgrounds and CFL Light Source
Glow in the dark stars painted on dark backgrounds and charged for 30 minutes by CFL light will glow very bright as soon as you turn off the lamp but will start to fade pretty quickly.
The main constellation stars will almost certainly glow for several hours. The smallest stars will glow might not even be visible. Effects might only be barely visible if painted with the brightest green or aqua paints.
Light and White Backgrounds and Incandescent Light Source
Incandescent bulbs are at the bottom of the ladder. They work but just not as well as CFL’s. So this can be a good opportunity to go change out the incandescent with CFL’s. You could also factor in the cost of doing this upgrade as part of painting the room.
Only the brightest glow in the dark paints will have any lasting duration. It’s just not practical to paint any effects of tiny stars if using incandescent light to charge the paint.
Dark Backgrounds and Incandescent Light Source
This should be avoided at all costs. Only paint these rooms if you can upgrade the lights to CFL’s.
Rooms with Recessed Lights
Rooms with canned, or recessed, lights need to be avoided. Canned lights will not charge the paint at all. The paint requires direct light and not reflected light which is all that the canned lights will produce. For rooms where canned lights are present a UV lamp or other source of light must be used.