Here is a Slim Jim I finished for an upcoming NCOWS Convention raffle. I've found that my current batch of Walnut Dye (brewed with actual Walnut Hulls) is on the strong side. Also every hide seems to react differently. What I've got in the habit of doing is testing small pieces from the specific project before dyeing. I tested this one at two, four and six hour immersion times. This Holster was immersed in the Walnut dye for 1-1/2 hours followed by two coats of Neet's Foot Oil and two coats of Skidmores. It has some variance in color probably due to my overdoing the first coat of Neets but I am getting closed to the color I'm looking for.
The first picture shows the Holster after drying but before oiling along with the two hour sample.
I wish I were a better Photographer. The pictures do not show the colors as they actually look. The six hour sample was the darkest.
I'm also following Cliff Fendley's advice. I have two five gallon buckets of Walnut Hulls brewing outside over the winter.