A black-and-white-looking photograph is not automatically a 1-bit deliverable. Grayscale can contain many tonal levels. A bilevel image represents only two levels, and the saved file must use the encoding the supplier requested. Even an RGB picture containing only black and white pixels is not necessarily stored as a 1-bit image.
Confirm why the production workflow asks for it
Ask for the accepted file format, required dimensions and the interpretation of black and white. Do not infer that every monochrome print, engraving or two-ink process needs the same file. A studio requesting grayscale tonal plates may have a different requirement from a device expecting a bilevel bitmap.
Adobe's Bitmap conversion guide distinguishes threshold and dithering approaches. Its color-mode guidance separates Grayscale and Bitmap. These external controls are not a claim that Imagild exports a supplier-ready 1-bit production file.
Compare two conversions before choosing
For a fictional portrait label, retain the original color photograph and the approved grayscale master. On separate copies at the intended dimensions, compare a threshold conversion with a supported dithering method. Threshold maps tonal values to either of the two levels according to the threshold; dithering represents tonal appearance through patterns of the available levels. Neither is automatically appropriate for the receiving machine or material.
Inspect a recognizable eye, a hair boundary and the smallest verified text. A smooth gray cheek may turn into a large solid shape, while a fine dither can become unsuitable speckle for a particular process. Judge the conversion at the final physical size and consult the supplier rather than selecting it only from an enlarged screen view.
Copyable production brief
Prepare the approved portrait for the supplier's stated 1-bit workflow at its required dimensions and accepted encoding. Keep color and grayscale masters unchanged. Provide separate threshold and dither proofs for review, identify which one is selected, and verify the saved file's actual mode or bit depth in a suitable inspection tool. Do not assume a .bmp extension or a two-color RGB preview proves compliance.
This is a proposed comparison, not a completed print test. Obtain the supplier's confirmation of the chosen file before committing to production. Exact wording should remain independently verified, regardless of the selected tonal method.
Approve both the file and the visible information
Reopen the exported deliverable, confirm the requested structure and inspect whether important features survived. A technically correct 1-bit file can still contain an unreadable face or broken lettering. Conversely, a visually convincing two-color screenshot can fail the required encoding.
Imagild can help prepare the creative image, but use an appropriate external tool for this conversion and file inspection. Retain the grayscale master so another production process does not have to begin from the restricted two-level copy. Acceptance means the supplier receives the agreed technical file and the proof preserves the approved information; it does not mean that all future monochrome uses should reuse this same conversion.