Silvering, Future, and White Paint

Although Future is among the most stable of acrylic polymers, it will yellow over time, especially if exposed to ultraviolet radiation from any source. This includes the liquid in the bottle. It was never meant to be stable for fifteen years. So get a new bottle. Remember that it is now called "Pledge Premium Floor Finish with Future Shine." Marketing wonks!

The discoloration is more noticable when brushed because brushing produces a thicker film. 

Hey Wilbur,

It might sound a silly question but why not start with gloss white and skip the Future?

To answer your question, Phil, gloss whites (and yellows, oranges, etc.) have even less hide than flat whites. In general, a flat paint will have a higher hide value than the same color in gloss. In white, this is caused by use of a different white pigment, a higher pigment load, and the use of "flatting agents"—pigments that increase hide as well as reduce gloss. In the case of other colors, the primary cause of higher hide is the use of a higher pigment load and flatting agents.

There is a limit to the amount of pigment that can be put into a gloss paint before the pigment load affects the gloss of the cured film. 

Ah! I misunderstood your point. That is, indeed, what I usually do with white.

I also undercoat white with silver, which reduces the number of coats of flat white needed, considerably.