Reading the board
Each card shows the largest print the Met's file makes at 300 dpi without cropping — that's the sharpness you'd want for something you'll stand close to. The biggest file in this set isChrist's Entry into Brussels in 1889, at 12,900 × 7,352 pixels: enough for a 43 × 24.5 in print at 300 dpi, or 86 × 49 in at poster sharpness.
Every page has a size chart against standard frames, the museum record, and the frame and light that make a print look like it cost more than it did. The file itself is free. It always was.