Ok. I use PPG so i could have gave you a detailed description on what I do. Ultimately you'll want a sheen in the middle of eggshell and flat. Thats what i use on dash pads. I quick looked up dupont paint on how they mix the flattening agent, and looks like you have semi gloss, eggshell, and flat, to choose from. If i was doing it, I would add a little more flatter(half of the weight of volume in between eggshell and flat) to achieve in the middle of of eggshell and flat. So if you needed 100 grams of flattening agent to get eggshell, and flat called for 150 grams, i would mix 125 grams. Again, i only did a little research on dupont. When i use ppg, I use MC02 Sheen which is a Matte finish. It gives it a nice velvet look.Definitely not a rattle can. My painter use's Dupont or Sherwin Williams. Two stage he told me.