Scanning Guidelines

Standards

In order to scan to Maryland State Archives standards, first and foremost, the images must be a complete and accurate reproduction of the original. In order to meet these standards, we make the following scanning recommendations

Recommendations

1. General requirements for scanned text:

• Bitonal (1-bit black and white) images must be scanned at 300-600 ppi. Scanning at 600 ppi is recommended. This is appropriate for documents that consist exclusively of clean printed type possessing high inherent contrast (e.g., laser printed or typeset on a white background);
• Grayscale (8-bit) must be scanned at 300-400 ppi.(This is appropriate for textual documents of poor legibility because of low inherent contrast, staining or fading (e.g., carbon copies, thermofax, documents with handwritten annotations or other markings), or that contain halftone illustrations or photographs )
• Color (24-bit RGB [Red, Green, Blue]) must be scanned at 300-400 ppi. Color mode (if technically available) is appropriate for text containing color information important to interpretation or content.

2. Output Format:

• Preferred File Formats: Tiff ( Group 4, Uncompressed) , PDF/A
• Accepted Formats: JPEG

3. Compression: no less than 85% to avoid significant image degradation

4. Polarity: 100% positive polarity (i.e., black writing on white background). This is especially important to note in the case of imaging negative photostats with marginal notes

5. Placeholders: If a page of the original is missing we strongly recommended that the Agency create and insert a placeholder image identifying the missing document and the reason that it was not imaged. This is an excellent tool for making sure that every page of a document is accounted for

6. Quality Control: Someone other than the scanner should perform a quality check of each image to ensure that

1. the image is an accurate reproduction of the original and is clear and readable
2. the directory and filename for the image accurately identifies the record imaged

The above is general guidance on scanning. Learn More: Digitization Guidance Guide