I have a picture of a lovely blue soap..a rich blue. The poster said they dissolved indigo in the lye solution. I tried this. 1 tsp/lb...it ended up a muddy grey color. How much indigo should I use per lb?
Also does anyone have suggestions for a bright spearminty green that does not fade...nature?
I think you are going to have a tough time with the "not fading" part. Spirulina fades and turns a yucky sort of pale pea-green-brown. French green clay doesn't fade, but it's a very pale, soft green.
Indigo can be a BUTT! I have created both a crayon bright blue blue and a faded jeans grey blue using the EXACT same methods & recipe (as far as I could tell). That was both by adding indigo to the water before the lye, and using the split method and adding indigo water to the soap batter. I have used 1/4 to 3/4 tsp per lb of soap, I think my best results were at 1/2 tsp per lb. I have never gotten a bright blue adding the indigo powder to the batter.
For green I would recommend a green oxide."Natural" green seems to fade in CP soap (I have worked with spirulina, comfrey, nettle and green seaweed, they all seem to fade towards olive drab khaki). I comfort myself with the idea that an oxide is like rust, and rust is perfectly natural
From personal experience I can add to the natural greens that fade/morph to yucky green/brownish -- chlorella. My preference for natural green is green clay. It is subtle and on the gray side, but a lovely color nonetheless.
Spirulina did not work for me at all. It's extremely photosensitive and fades in even the least bit of light. What I like to use for all natural green colorant is spinach powder. The color has much more staying ability. Chromium Oxides is my go-to for greens, but if I'm going natural or want a specific look, spinach powder seems to be the way to go.
As for the indigo, I've read that adding the indigo to the lye water is supposed to create a richer color, but personally I prefer to infuse it in a little bit of oil and add it to the soap batter at trace (just as you would with an iron oxide or ultramarine).
I'll post a pic of a soap I did a few months ago that has half spinach powder and half indigo. This was for roughly a 5.5 lb. batch, and I used 2 tsp. of indigo powder to color half of it. So we're looking at 0.75 tsp. or so per pound of soap (not oil), and I'd say that you could probably go up to 1 tsp. per pound of soap or more without the bubbles discoloring.
ETA: This batch is 4 months now, and the color is sticking just fine.
Also, you may want to check the oils in your recipe to see if they are responsible for skewing your colorant. A whiter bar will highlight the true color better than a recipe that's a yellowish or greenish.
I have a picture of a lovely blue soap..a rich blue. The poster said they dissolved indigo in the lye solution. I tried this. 1 tsp/lb...it ended up a muddy grey color. How much indigo should I use per lb?
Also does anyone have suggestions for a bright spearminty green that does not fade...nature?
I've used indigo powder several times and always at about 1/2 teaspoon per lb of oils. I add it to my lye too, otherwise I have trouble with it mixing in. I've attached three photos:
1) The indigo in just a regular CP. I love this brilliance the best.
2) My salt soap batter. It has a greenish tinge instead of pure blue before the batch is cured.
3) My salt bars (with that same ratio of indigo) from the greenish-blue batter. In the salt bars, the color fades to a bluish gray.
