Virginia Administrative Code
Title 17 - LIBRARIES AND CULTURAL RESOURCES
Agency 15 - LIBRARY BOARD
Chapter 20 - STANDARDS FOR MICROFILMING PUBLIC RECORDS
Part V - Microfilming Procedures
Section 17VAC15-20-70 - Densities
All densities shall be as consistent as possible throughout the microform. The background density of the camera negative microfilm shall be within the ranges shown in the following table when measured on a blank area of the filmed document.
| TABLE 1. BACKGROUND DENSITIES. | ||
| Classification | Description of Documents | Density |
| Group 1 | High quality, high contrast documents or printed material and black typing; fine line originals, black opaque pencil writing and documents with small high contrast printing; Pencil and ink drawings, faded printing and very small printing. | 1.00-1.20 |
| Group 2 | Low contrast manuscripts and drawings; graph paper with pale, fine-colored lines; letters typed with a worn ribbon; poorly printed, faint documents; and positive appearing photostats and blueprints. | 0.80-1.00 |
Background density on positive appearing camera microfilm shall be no higher than 0.30. The base-plus-fog density of unexposed, processed, clear-base film must not exceed 0.10. When a tinted base film is used, the density shall not exceed 0.30. Measurements are made using a densitometer calibrated with a step tablet provided by the Imaging Services Branch, LVA. In certain instances, some poor contrast documents may require lower densities to make the entire image legible and reproducible as stated in ANSI/AIIM MS23 - 1998. Mixed quality documents should be filmed at the lower densities. A system of inspection and quality control to ensure compliance with this standard shall be established and consistently maintained in conformance with ANSI/AIIM MS23 - 1998 Practice for Operational Procedures/Inspection and Quality Control of First-Generation, Silver-Gelatin Microfilm of Documents.
Statutory Authority
§§ 42.1-8 and 42.1-82 of the Code of Virginia.
