I have NO idea what kind of 'oil base' formula you're going to get from a reputable automotive paint supplier.... however, even if they WILL sell you something oil-based.. DONT put it on your bike.
I THINK what 2wheels was trying to get at was a 'SingleStage' paint, which you can get a flattening agent added to for a matte look. HOWEVER... as I (and others) have posted MULTIPLE times on here before... Single-Stage IS NOT FUEL-SAFE. It's enamel. Just like spray paint. First time fuel touches it, it's going to melt instantly.
To achieve the flat-black look AND be fuel-safe, you MUST use a catalyzed clear over the top of the color (usually black... ). "Clearcoat" doesn't NECESSARILY mean glossy. It IS possible to spray a clear with a matte finish. PPG and Doupont sell deglossing agents that you can add to any catalyzed clear OR enamel to keep the surface from achieving gloss. HOWEVER... these deglossing agents are not UV-safe and will 'chalk' after a few seasons use. That means that the surface will become dry and powdery, to the point where you can draw marring marks with your finger on it.
IN MY OPINION... the easiest, cheapest, and fastest way to achieve the desired 'flat black' look is to use DBC-500 mixed 6:6:1 with proper speed reducer and DCX51 hardener. DBC500 is an intercoat clear. It's kind of like a 'clear-paint' instead of having all the super-duper stuff that 'regular' catalyzed clear has in it.. DBC500 is pretty much just the bare necessities (and costs about 1/5 what a high-quality clear does). The problem: PPG WILL NOT give you any specsheet showing that DCX51 works with DBC500. It DOES work, PPG knows it, and so do custom paint shops. DCX51 is the catalyst for the 'regular' clears. Typically, DBC500 just gets mixed with reducer, just like your basecoat colors; 1:1.
As the DBC doesn't have all of the flow agents and other goodies that 'high quality' clears have, it doesn't achieve a glossy surface very easy. For a bodyshop, that's bad, cause your sprayer has to work pretty hard to get that glossy look out of DBC500. For someone with a cheapo-gun, little experience and no money to do it over.. this is a selling point of DBC500. If you stand back and 'fog' the panel, it will come out super-flat. If you lay it on a bit thicker, it will be a bit more glossy, but not shiny.
Adding the DCX51 to the DBC500 causes the DBC500 to be fuel-safe and super-hard (like regular glossy clear) when it dries. It increases the drying time by about 1/2 hour, but still, your overall tack time is like 15mins, and your colorsand time is about 2 hours, depending on your film thickness.
Oh.. and all of you who want a 'flat black' bike and are using actual "Black-Black"... quit it. Go ask for "Lamp Black". It's a super-dark grey that looks better as a 'flat black' than if you just spray black with no gloss....
Here's a pic of a bike that was done in lamp black with DBC. This is NOT my paintjob... just a reference photo.
And another
