Soft proof / hard proof
A soft proof simulates the printed result on a calibrated screen. A hard proof is the physical sample you hold before approving the run.
See it
What it is
A soft proof is your file viewed through the output profile on a calibrated display, so the screen fakes what ink on that paper will do. It is free and instant ('Proof Colors' in Photoshop, proof setup in InDesign and Acrobat), and it is only as honest as your monitor calibration and the light in your room. A hard proof is a physical object: a calibrated inkjet contract proof, a sample off the digital press, or a full wet proof run on the actual press and stock.
Soft proof constantly, while you are still designing, to catch out-of-gamut brand colors and blacks that will collapse. Order a hard proof once, before the run, on anything expensive or color-critical: packaging, a brand launch, anything with skin tones. Signing a hard proof usually transfers responsibility, so what you approve is what you own.
Gotcha: know what a proof is actually promising. A contract proof is normally printed on certified proofing media chosen to simulate the target press condition, not on your final stock, so it can nail the color numbers while telling you nothing about texture, absorbency, paper white, or finish. When those have to be judged with a thumb and an eye, order a press proof or a production sample on the real sheet and pay for it. Either way, judge under D50 viewing light rather than office fluorescents, and never compare a proof to a screen sitting right next to it.
Ask AI for it
Set me up to proof this print file properly. First, walk me through soft proofing it in [tool] using the printer's ICC profile with relative colorimetric intent, black point compensation on, and paper white simulation on, and list which brand colors and photo areas fall out of gamut on this stock. Then write the exact request to send the print shop for a hard proof: state whether you need a contract proof on certified proofing media simulating this output condition, or a press proof and production sample on the actual stock because texture, paper white, and finish have to be judged physically, and say which one this job justifies. Include the D50 viewing condition and a checklist of what to inspect and sign off before the full run starts.