Dyeing: leather stiffness

[NVLeatherWorx]

As already noted you will get a ton of answers and tips and they all work well for those who offer them.  Regarding whether or not oil/conditioning is necessary the short answer is yes and here is why:  every time you touch the leather you are removing some of the natural oils that are in the fibers; every time you apply a spirit based product you are again removing some of the natural oils from the fibers.  These oils need to be replenished so as to keep the leather pliable and proper but you don't need a lot of oil to do this.  First, you want to make sure that you are using ONLY Pure Neatsfoot Oil, it doesn't smell and it doesn't have any additional chemicals in it like the compound versions do (those chemicals actually counteract the oil benefits and they create a much darker finished look).  Only apply it in light coats, let it set for a few hours (I leave mine for at least 8 hours) and then apply again as necessary.  If you do it right you will not see a noticeably darker color for your final look but if you overdo it you will see the colors as much darker and your leather will sweat oil for a very long time.  I apply a light coating before I do any dyeing/staining which helps you get a more even application of the color and the pigments also tend to set a bit better; I apply another coating after it has all dried to give back some of what I have taken away from it during the process of adding color.  Once all is said and done I final seal everything with a coating of my own leather conditioner (a blend of beeswax, cocoa butter, and Pure Neatsfoot Oil) so that it has a good outer seal, gets a bit more oil for conditioning, and has a protective layer to repel moisture long enough to get your leather gear in a dry and protected area.

For dyes I only use Fiebing's Pro Dye (and have been using it since it was first introduced; used Fiebing's Dye ever since I started working with leather).  I find that the Pro Dye has a more even coverage on first application and has a flawless coverage on the second application (both of them light to medium application).  The Pro Dye also has a more consistent pigment dispersion and is a bit slower on the drying time (the spirits don't evaporate as fast as with the regular dye versions) so you get a better color set overall.

[ABHandmade]

You can also try spirit dyes Toledo Super (manufacturer KendaFarben, Italy). They give an even color (you could see an example of their use in my wallet with roses, there everything — the background and the image — was made by them) and dry the leather very weak.
They are perfectly diluted with isopropyl spirit, which makes it possible to obtain the desired shade. In addition, applying several layer diluted dye gives a much more even color than 1 time undiluted - this has already been mentioned here.
There is one peculiarity - they become brighter when the finish is applied or when treatment by oil .

The only drawback is a strong odor, but this is common to all spirit dyes.
As an oil for impregnation, I use refined mink oil. From my point of view, it works more delicately than neatsfoot. But this is my subjective opinion.
Again, according to my observations, for soft leather a small use of oil after dyeing is desirable. For tough leather it is a matter of taste and habit