If you’ve made the time to experiment and measure out how much color you use each time you make soap, you may know how much color you’ll need to achieve the results you’re looking for. But if you’re somewhat new to the soapmaking world and haven’t made dozens of batches yet, there isn’t a whole lot of information from suppliers about usage rates. I’ve seen things like “add desired amount” or “if your soap lather is colored, you’ve added too much”. Well, that’s not so helpful since you can’t really judge that until after the soap is set up and you’ve already ruined it! Sometimes the supplier will tell you how much color to use per pound of oils. Rarely do I color an entire batch of soap the same color anymore. It’s usually pulling out a cup of soap, or splitting the batch into smaller parts to do a design.
I’ve come up with my own basic usage guidelines for the various types of micas and pigments like oxides and ultramarines. I’ve also experimented with neons which will give a very nice range of color. These are the guidelines I use PER CUP of soap:
Micas – I use 1 tsp. per cup of soap for the most brilliant color
Oxides and ultramarines – Use 1/4 tsp. per cup of soap
Titanium dioxide – use up to 1 tsp. per cup of soap. (Less is better!)
Neons – Use 1/2 tsp. per cup of soap for the most brilliant color, 1/8 to 1/4 tsp. per cup for pastels or lighter colors.
(These are my own guidelines. It’s always a good idea to do your own testing!)
Pre-mixing your colorants: You’ve probably seen soapmakers using glycerin, oil or water. How do you know which one to use? Glycerin is a safe bet because it will mix with both water and oil soluble colorants. That’s why you can buy colorants pre-mixed with glycerin from soap supply vendors. It’s also easy to clean up! The only issue with using glycerin is that you absolutely have to stick-blend the colorant into the soap to get it fully incorporated. This works most of the time – it’s just when you need your soap batter as fluid as possible for an intricate design that you wouldn’t want to stick-blend the color in. It’s also more difficult to tell how much colorant you are using when you purchase it pre-mixed, so you’ll just have to eyeball it.
I prefer to mix my colors with water whenever possible – even micas that don’t seem to incorporate very well. That way any extra liquid I’m adding to the soap will just cure out. You can test oxides and ultramarines to see if they mix better with oil or water. Titanium dioxide will be labeled with its solubility, and I like to get the water soluble variety. Most ultramarines and all neons have to be mixed with oil, however. You can use some of the oil from your recipe if you remember to do it that way, or just add a tiny bit extra to the colorants.
Clumping is another issue you might be having even with pre-mixing – especially with oil-soluble titanium dioxide, oxides and ultramarines. Using a mini frother will help remove all the clumps in a hurry. If you don’t have one, I suggest pre-mixing before you start the rest of your soap preparations and give it a stir every once in awhile as you walk by.
Offsetting yellow tones or discoloring fragrances with titanium dioxide: Titanium dioxide is a strong whitening agent in cold process soap. You can use it to off-set the natural yellow or beige tone of your soap to create a white soap, or use a small amount with your colors to make them lighter or more pastel, and especially if you are using a fragrance oil that discolors to a light to medium tan it will help retain the color of your soap. Using whiter oils in your soap base will also help! If you have a fragrance that is mostly vanilla, or you know it will turn dark brown, it’s an exercise of futility to try to work against it. Titanium dioxide will not offset it, and vanilla stabilizers tend to break down over time. You can either add fragrance to a portion of your soap so that only that part will turn dark brown, or just go with it and have a soap that is completely dark.
What about the crackle effect from titanium dioxide? Sometimes you will get a crackled soap from using titanium dioxide with a soap recipe that overheated. There are certain fragrances that will overheat your soap, such as many of the florals, as well as certain oils in your soap recipe that can cause problems. For example, after I removed rice bran oil from my recipe, the amount of crackling from titanium dioxide was drastically reduced. Since it’s just a cosmetic issue, you don’t have to worry about it affecting the performance of your soap, and sometimes it just looks really cool! Use the least amount of TD you can. Using too much can cause your soap to become brittle, so no more than 1 tsp. per cup of soap. Seasonal changes can affect your soap, so remember it’s not necessary to over-insulate your soap in the warmer summer months!
How do you get a true red? This used to be a more elusive problem, but I’m seeing more suppliers who carry the true red, non-bleeding colorant. Most of them are pre-mixed, however, so if you want to get more bang for your buck, you can order the powdered form from TKB Trading – red lake #30 – and mix it yourself with either oil or glycerin. Nurture Soap has a Really Red colorant, and Mad Micas has a true red set.
Morphing colors: low ph dyes will morph in a high ph environment. Sometimes you can make the color changes work for you, such as a blue that turns purple. Sometimes a blue will just turn a nasty gray though. If you want a true blue, stick to ultramarine blue or a mica that you know is stable. I can recommend soap stable micas from both Mad Micas and Nurture Soap.
Bleeding colors: Most FD&C and D&C dyes will bleed and/or fade in sunlight. I usually avoid these for soapmaking. If you buy soap colorants from the hobby stores, they are made for melt & pour bases and they are usually FD&C or D&C dye that are highly diluted and will bleed and fade in cold process soap. Be sure to purchase high quality micas, oxides or ultramarines from a reputable soap supply vendor or get the Lab Colors that are specifically for cold process soap from Brambleberry.
If you are more of a visual learner, please watch this video I created for more information:
More resources from Anne-Marie Faiola of Brambleberry:
More information on using titanium dioxide to off-set dark oils from Majestic Mountain Sage:
There is so much information around using colors in cold-process soap. I’ve only hit the tip of the iceberg, so if you have more questions, please ask in the comment section below!