How are guys matching factory paint ?

Not sure what you’re trying to say there, Kim ?

It's called a Spectophotographer. They use this tool to scan your existing paint, then it gives them a formula to mix a match to your paint.

As with any bodywork/paint repair, you have to do the Paint to Match theory. Basically using a body line to break between old an new paint. Finding the least conspicuous area to do the final blend if doing a spot repair.

So you get the closest possible match, some professionals can tweek to match the final custom mix to get it as close as they can. Then they Paint to Match.

Basecoat/Clearcoat paint systems offer excellent blending capabilites with the clear coats, better than the single stage acrylic enamels that a lot of the early A bodies were painted with.

But yes Acrylic Enamel, still Paint to Match.