I would prime with oil based primer that is a sealer too, otherwise the knots will all bleed through. However, I would not paint it black. Blazing hot in the summer is not a good thing. A regular barn red would be my choice.

What type of pine?

Smooth or rough?

Green or dry?

All full height boards?

T&G, shiplap, B&B or?

Why black?

Who is doing the painting?

If you don’t like a standard barn red, how about green?

A stain may have more longevity than a paint job. Pine can absorb stain unevenly which may be less of an issue with a solid stain than a translucent stain.

Yea, I wouldn't do black either. Barn red is a classic, but a green would look good, too.

Painting new pine requires homework. I would not use paint. You don't need opaque Tricorn black (IMO). The goal aesthetic is a dark barn, not to use SW Tricorn Black.

The products I'd investigate first are:

• Armstrong-Clark Black Walnut
• TWP Black
• Sansin Ebony
• PPG ProLuxe Ebony
• Cabot's Australian Timber Oil in Jarrah Brown (not black, but can read almost black on pine)

You need to plan for recoats process, not just first color application. Armstrong-Clark is the best bet here.

A friend used the PPG Proluxe on his barn and it has held up well.