Jimble mate, have you seen those kits at sh!ttly halfords ?? they are chip repair kits and on the very end is like a needle with a tiny hole in, these are bad boy!! cant believe nobody else does their touch up kits this way, absolutly perfect for small stone chips i did my full front bonnet, as i had loads i wet sanded it, this was around 3 years ago - stll looks mint, the colour match was spot on too. deffo worth a look.
They are in containers with a primer stick, colour stic and top coat, all in like a thin plastic container with clear lid/silver base