i used paintbrushes on the small areas and a airbrush on the fades....let me tell you i have never picked a airbrush up till i got into leatherwork ...and it was not as scary as i thought a little practice and you can be fading colors by thee end od the day....i used spirit dyes cause acylic pigment need to be dilluted down and to get the right consistantcy is a bitch. it kept clogging my tip up ....if you r going to try acylics you can take liquidex airbrush medium ,it is used to cut and thin the colors, so you can make it flow through the tips .....50 /50 cut is a good place to start but you will have to adjust based on brand of paint ....if u use dyes (fiebings my choice) u use it straight out the bottle ....for this project i used mohagony on the very edge then dark brown , then light brown (all fiebings) ...aprayed most of the area with light color then moved outward with each darker color as they mix alittle it blends as a gradient .....like i said this is all new to me so its trial and error but in this paticular case that is how i stumble though and made this item ....so dont take this as a rule ...but a startin point ....hope it helps ....so much info on this site ...just trying to contribute im out!