What does "almost clear" really mean?

Glow in the dark paint marked "almost clear" is translucent.  Therefore, it is barely noticeable during the day if it is painted onto a white or light surface.  There is no such product as an "invisible" glow paint as you may have seen wrongfully advertised.

Glow in the dark pigment unlike regular pigment does not dye it's paint medium.  It is actually microscopic particles that are suspended in the paint.  The light from these particles illuminates the paint medium, which produces the glow in the dark effect.  When the light in the room is greater than the light produced from the glow particles, they become almost invisible.

The translucent white glow in the dark particles only populate a small percentage of the paint versus the clear paint medium.  Therefore, on a light surface, these microscopic particles are almost impossible to see.

On a dark surface, it has the effect of a color lightening tint.

As you increase the number of glow paint layers, you also increase the number of glow particles in every square inch.  This has the positive effect of increasing the glow brightness.  But, it has the negative effect of making it more visible during the day.

Although I have said the particles are white, you may notice that glow pigment has a color tint as well. This is because glow in the dark powders are definately glowing while in the lit room.  But, the light in the room overpowers their glow.  The resulting glow appears more like a tint.

Our "Daytime" named products have a real color pigment added among the glow pigment.  They therefore dye the paint medium and act similar to a normal paint with an opaque color in a lit room.