How do you catch CMYK color shifts before the press run?

RGB to CMYK conversion surprises almost every client who hands over bright digital assets for print.

What looks vibrant and neon on an OLED screen always ends up looking muddy and flat on standard cardboard unless you manually boost the ink curves.

Spot UV layer separation errors are a close second getting a file where the varnish mask is accidentally merged into the black text plate is a total nightmare.

Do you print physical proofs in house first or do you just sign off on digital press proofs?