A black-and-white print can acquire a green or purple appearance through the file, print mode, paper-and-ink combination or viewing light. Test a known neutral grayscale strip alongside the photograph and keep the light consistent. Do not tint the master in the opposite direction before locating the source of the cast.
Confirm whether the source is neutral
Open the actual delivery file in a suitable editor and inspect representative gray areas. A visually monochrome image can still contain an intentional warm or cool tint. Keep that creative tone separate from an unintended cast introduced during printing.
Make a neutral test strip with several light-to-dark steps and print it using the same settings as the image. If both the strip and photograph shift similarly, investigate the output route. If only the photograph shifts, inspect its source and treatment before changing the printer.
Check the supported print mode
Some photo printers offer a dedicated black-and-white mode with neutral or toned options. Epson's model-specific guide documents such choices and their color-management requirements. This does not mean every printer has that mode, or that a grayscale file must use only one ink.
Use the correct paper setting and the chosen route's documented color-management instructions. Avoid combining a dedicated driver mode with an unrelated application profile unless the workflow supports it. Also check printer condition according to the manufacturer's maintenance procedure before altering image colors.
A hypothetical family portrait proof
Imagine a neutral family portrait and grayscale strip both look slightly purple on one paper. Under a different room light the appearance changes. The photographer repeats the comparison under agreed light and tests the supported neutral printing route, preserving the image master unchanged.
This is a hypothetical diagnosis. It does not prove the paper or printer is defective. The relevant evidence is which condition consistently changes the cast; multiple variables changed together would make the comparison inconclusive.
Keep creative toning deliberate
If the project wants a warm archival interpretation, approve that tone knowingly. If it wants neutral gray, compare against the neutral strip rather than against a bright screen in a different room. Ask a print supplier for an appropriate proof when the result matters.
An Imagild monochrome artwork can be used as the source, but check whether it actually contains a tone. The printed appearance is an external output question, not evidence that the generation prompt failed.
Acceptance
Inspect the chosen proof under the intended viewing light, with useful grayscale separation and no unapproved cast. Save the paper, print mode and conversion settings. A successful test on one medium does not certify another. Preserve the neutral master so future printing routes can be evaluated without accumulated compensating color edits.