Mixing dyes and multicolor pieces

[Inky Doc]

I have been trying to follow info on different threads about darkening dyes. I am using Fiebing’s leather dyes (Not Pro dye) and tried mixing 5 parts Navy Blue with 1 part USMC Black to get a very dark blue. When I applied it to the leather it was splotchy and uneven. I’m trying to do a darker version of the American Flag. I’m also using a small paint brush to apply. I know the dye is supposed to be spread with a dauber or sponge but obviously that won’t work for what I’m trying to do. Should I thin the mix with denatured alcohol? Also, how do I go about applying dyes intricately and keep them as even as possible? Any advice is appreciated. 

[bikermutt07]

I think for this I would switch to Angelus leather paint. 

 It sounds like you are trying to paint with dye. And that probably isn't going to go well. 

Someone with more experience should be along soon. Good Luck.

[VabaX]

1 hour ago, bikermutt07 said:

I think for this I would switch to Angelus leather paint. 

 It sounds like you are trying to paint with dye. And that probably isn't going to go well. 

Someone with more experience should be along soon. Good Luck.

Not unless you're airbrushing with stencils/shielding

I feel like I have seen some works that appear to have been 'painted with dye' after tooling, but thatd be a little bit different to doing it on untooled leather

[Stetson912]

Peter main has a book on coloring leather. He uses dye diluted in isopropyl alcohol I think.

Making it darker I don't know about. It makes sense mixing with black. But if it isn't working right I can't comment why. I don't know squat about color theory etc. 

Fiebings also has acrylic dyed in a lot of colors. Maybe there is something there that would work for you.

You should be able to use a brush to paint withdyed, I don't see why you couldnt.

[DJole]

8 hours ago, Inky Doc said:

I have been trying to follow info on different threads about darkening dyes. I am using Fiebing’s leather dyes (Not Pro dye) and tried mixing 5 parts Navy Blue with 1 part USMC Black to get a very dark blue. When I applied it to the leather it was splotchy and uneven. I’m trying to do a darker version of the American Flag. I’m also using a small paint brush to apply. I know the dye is supposed to be spread with a dauber or sponge but obviously that won’t work for what I’m trying to do. Should I thin the mix with denatured alcohol? Also, how do I go about applying dyes intricately and keep them as even as possible? Any advice is appreciated. 

I am no expert on the chemistry of dyes and dye mixing, so I don't know why your dye is splotching. I look forward to an expert chiming in to explain the problem. 
In the meantime, perhaps you can try another dye manufacturer. I find that Angelus works just as well as Fiebing's dyes. Maybe Angelus has the dye color that would match what you want-- there is a dark Navy Blue dye available:

• Dharma Trading has a lot of colors available: <https://www.dharmatrading.com/dyes/angelus-leather-dyes.html>
• Or factory direct: <https://angelusdirect.com/collections/angelus-dye-1>

I use a small paint brush frequently when dying leather. I haven't thinned the dyes out (although I do have a bottle of Angelus Solvent/ dye reducer for this purpose).
2 important things:
(1) wipe excess dye off the brush! Don't load the brush with a lot of dye, because once you touch the brush to the leather, suddenly a flood of dye will rush into the leather pores!
(2) work from the center of the area to the edge, to avoid dye going past the edge lines.
it's not really painting, but more like carefully daubing. 
As far as intricate dye application, small areas of dye shouldn't appear uneven. Big areas of dye have that problem. 

[Inky Doc]

I appreciate your input very much. Maybe I’m not daubing off enough of the dye before getting started. I’ll give that a try and I’ll look into other brands too. 

[Stetson912]

Angelus is very pigment heavy. More concentrated than most other dyes. As djole mentioned, angelus direct has all the colors you could want and I think they do have a dark navy. Their reducer is good for diluting their dye too, but you can also use isopropyl or denatured alcohol.