Lovely to have so many interesting replies. Thanks.
Frugalmax - yes, Reaper paints do have a Matt finish. Not as matt as one of other paint lines i looked when trying to choose (Pro Acryl I think it was). I now apply Reaper Sealer onto areas where I want a satin finish (e.g. leather) after I've varnished. But I do like the look to defaulting to matt because that's my personal preference. I also really liked Vallejo and would have gone with them for sure. But as a new painter with no experience mixing paints and no understanding of colour theory I found the Reaper range really helpful.