Bluing used in laundry. Why? How did it work?

I remember from years ago there was a liquid product whose brand name was Little Boy Blue Bluing. It was sold at stores in the soap powder section. I remember Mother using it in Laundry(white clothes I think). It was dark blue in color. Anyone know what it was used for? How? How did it work? Why isn’t it used now? Just curious.

Here is a website that describes the purpose of bluing.

Basically, it gives white clothes, linens, etc. the appearance of being super white by giving them a slight blue tint.

It probably isn’t used much anymore because it’s not a cleaning product; people today think that if a product is going to whiten clothes, it is going to do so by removing dirt, not adding a dye.

You can still buy bluing. I think I have some “Mrs. Stewart’s” brand around here somewhere. The basic idea is that since most white fabrics tend to look yellow when they get dingy, the slight blue tint counteracts it and brightens the white. Think of how white clothes look under a black light (which actually looks blue).

If any chemists or physicists would like to correct any errors here, be my guest.

One time Mr. S washed three brand-new white “event” T-shirts of mine (two were irreplaceable) with a red sock or something, and they were all pink. Careful bleaching, and then a liberal dose of bluing, made them white again.

The bottle also says it’s good for brightening white hair (think “blue rinse”) or WHITE PETS :eek: !

Don’t think I’d want to brush my teeth with it . . .

Like Scarlett said, white hair and white clothes, when they get discolored, tend to get a little yellowish. For some reason adding just a tiny bit of blue to them counteracts the yellow (you’d think it would make them green) and makes them look whiter than they did before the treatment.

People in the traffic paint industry, where all they deal with are white and yellow, sometimes use this principle to fix a batch of white paint that accidentally gets some yellow in it, and some white pavement markings have blue dye added (in tiny amounts) to counteract the yellow shade of the resins in them.

I think this tactic only works when something is just slightly yellow, because I know if you mix yellow paint with blue paint you get green paint.

I still use bluing - it does a particularly good job on cottons that have a tendancy to grey when washed in hard water.

You do have to be careful though - the bluing is added to the final rinse water - if you get it directly on clothes, it will stain.

I had a little white dog who spent 6 or so weeks kinda blue because of inadequate reading of the instructions…:slight_smile:

:stuck_out_tongue: Tee hee… Actually these days we use fabric brighteners like 4-Methoxy-N-methyl-1,8-naphthalimide or 7-(2H-Napthol[1,2-d]triazol-2-yl)-3-phenylcoumarin which absorb ultraviolet light and emit bluish light. This makes the whites appear whiter and the colors appear brighter, regardless of whether the garment is actually clean.

You have to understand the color wheel somewhat but blue is oppisit to yellow on the color wheel and oppisits will cancel each-other out. (I teach color to cosmotologest :smiley: )

also if you look at most liquid laundy soaps (and some powdered too) you will notice it has a bluish cast already. Why? to help make your whites brighter;)

well thats my 2 cents


Opposites on the color wheel may be complementary, but don’t make white. Yellow and blue definitely make green. Ask my 3-year-old son who peed in the toilet with the blue water :slight_smile:

I think that depends on whether the light is reflected or emitted (I remember the color-mixing display at the Boston Museum of Science) but damned if I can remember whether emitted blue and emitted yellow do something different than reflected blue and reflected yellow.

Yes. Here’s a nice description of additive and subtractive color wheels. Blue and yellow make white when the colors are additive.
The modern fluorescent brighteners have a couple advantages over bluing which explain their popularity.
• They can be added directly to the detergent powder or liquid.
• They are not blue. Instead they absorb invisible ultraviolet light and emit blue light.