Definition |
The physical characteristics of a microform material. |
| BKS, CNR, SCO |
Use for microforms. If you are describing different versions or variations of microforms in a single record, use separate 007 fields for each version or variation. |
| VIS |
Use for microform reproductions of existing graphic materials and for microforms that are components of kits.
If you are cataloging a reproduction that is not a microform (e.g., a video copy), use the 007 applicable to the reproduction. |
| Archival material |
Use only if the entire item is microform. |
| MAP |
Use only for cartographic items that are microforms. Use
field 007 maps for all other maps. Use
field 007 globes for globes. |
| All formats |
007 is valid in all formats so you can code for the physical characteristics of the parts of an item such as accompanying material. |
1st Indicator |
Undefined. The 1st indicator position is undefined and contains a blank ( ). |
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Undefined | |
2nd Indicator |
Undefined. The 2nd indicator position is undefined and contains a blank ( ). |
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Undefined | |
Subfields |
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‡a Category of material |
The category of material to which the item belongs is a microform. Microform is a generic term for any medium, transparent or opaque, bearing microimages. A microimage is a unit (e.g., a page) of textual, graphic or computer-generated material that is contained on aperture cards, microfiche, microfilm, microopaques or other microformats and that is too small to be read without magnification. A microform may be reproductions of existing textual or graphic materials or they may be original publications.
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‡b Specific material designation |
A one-character alphabetic code that describes the special class of material (usually the class of physical object) to which an item belongs (e.g., a microopaque). A fill character (  ) is used when no attempt has been made to code this position.
| a |
Aperture card. An aperture card is a card with one or more rectangular opening(s). |
| b |
Microfilm cartridge. It consists of a strip of photographic film wound onto a single core (or hub), housed in a protective container. |
| c |
Microfilm cassette. It is a strip of photographic film wound onto a double core, housed in a protective container. |
| d |
Microfilm reel. It consists of a strip of photographic film wound onto an unenclosed flanged holder (or reel). |
| e |
Microfiche. The item is a microfiche, i.e., a transparent sheet of photographic film containing microimages arranged in a grid pattern (a two-dimensional array) and having a heading that contains identifying information in text that is large enough to be read without magnification. |
| f |
Microfiche cassette. The item is a microfiche cassette. |
| g |
Microopaque. The item is a microopaque, a sheet of opaque material bearing a number of microimages arranged in a two-dimensional array. |
| u |
Unspecified. The specific material designation is not specified. |
| z |
Other. A type of microform for which none of the other codes is appropriate. | |
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‡d Positive/negative aspect |
The positive/negative polarity of the microform.
| a |
Positive. Indicates a positive microform in which lines and characters appear dark against a light background. |
| b |
Negative. Indicates a negative microform in which lines and characters appear light against a dark background. |
| m |
Mixed polarity. A microform with mixed polarity, i.e., a microform that is a mixture of positive and negative images. |
| u |
Unknown. The polarity of the microform is not known. | |
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‡e Dimensions |
The dimensions of the microform, not the dimensions of the image.
Microfilm
| a |
8 mm. Indicates the width of the microfilm in millimeters. |
| d |
16 mm. Indicates the width of the microfilm in millimeters. |
| f |
35 mm. Indicates the width of the microfilm in millimeters. |
| g |
70 mm. Indicates the width of the microfilm in millimeters. |
| h |
105 mm. Indicates the width of the microfilm in millimeters. |
Microfiche and microopaque
| l |
3 × 5 in. (8 × 13 cm.). The height and width of the microfiche or microopaque in inches or centimeters. |
| m |
4 × 6 in. (11 × 15 cm.). The height and width of the microfiche or microopaque in inches or centimeters. |
| o |
6 × 9 in. (16 × 23 cm.). The height and width of the microfiche or microopaque in inches or centimeters. |
Aperture cards
| p |
3 1/4 × 7 3/8 in. (9 × 19 cm.). The height and width of an aperture card in inches or centimeters. |
Other microform
| u |
Unknown. The dimensions are not known. |
| z |
Other. Dimensions for which none of the other codes is appropriate. | |
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‡f Reduction ratio range/Reduction ratio |
The reduction ratio range and the reduction ratio itself. Use four-character positions. The first character position indicates the ratio range.
| a |
Low reduction. (less than 16x) (less than 16:1) |
| b |
Normal reduction. (16–30x) (16:1–30:1) |
| c |
High reduction. (31–60x) (31:1–60:1) |
| d |
Very high reduction. (61–90x) (61:1–90:1) |
| e |
Ultra high reduction. (over 90x) (over 90:1) |
| u |
Unknown |
| v |
Reduction ratio varies |
The second, third, and fourth positions are the ratio itself. If the reduction is over 90x– (ultra high), you must enter the specific ratios. Otherwise, specific ratios are optional. If you are entering a ratio that is under 100, enter leading 0's for the second and/or third positions. If you do not enter the specific ratios, enter three hyphens in the second, third, and fourth positions.
| 007 ‡f b--- |
| [Normal reduction without specific ratio] |
| 007 ‡f c048 |
| [High reduciton ratio 48:1] |
| 007 ‡f e150 |
| [Ultra high reduction ratio 150:1] | |
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‡g Color |
The color characteristics of the image for microforms.
| b |
Black-and-white. The microform image is in black-and-white (usually black-and-transparent). |
| c |
Multicolored. The microform image has more than one color. |
| m |
Mixed. The microform is a combination of one-color and multicolored images. |
| u |
Unknown. The color of the microform is not known. |
| z |
Other. The coloration for which none of the other codes is appropriate. | |
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‡h Emulsion on film |
The type of film emulsion of the microform.
| a |
Silver halide. Silver halide is a compound of silver and halogens. Silver halide microforms are black and transparent. Most commercial microforms are silver halide. |
| b |
Diazo. Diazo is sensitized layers composed of diazonium salts that react with couplers to form dye images. The color of the image is determined by the composition of the diazonium compound and the couplers used in the process. The image may be black, violet, or another color. |
| c |
Vesicular. Vesicular describes films in which a light-sensitive component is suspended in a plastic layer. Vesicular films are commonly blue or beige. They do not appear to have much contrast (very high density) until projected. |
| m |
Mixed. A microfilm may have slices of film with one type of emulsion and other slices of film with one type of emulsion and other slices with another type of emulsion. |
| n |
Not applicable. Use for microopaques. Microopaques are not on film. |
| u |
Unknown. The item does not have emulsion on film. |
| z |
Other. Emulsion for which none of the other codes is appropriate. | |
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‡i Generation |
The copy generation of the microform.
| a |
First generation master. The first generation is the camera master or COM recorder master. Use for all master films made on archival stock in accordance with archival production standards and given archival storage under relevant ANSI/AIIM standards. |
| b |
Printing master. Microforms of any generation employed mainly for the production of other microforms. Used for all masters not manufactured, produced, and stored in accordance with archival standards. |
| c |
Service copy. Microforms that are for public use, rather than for production of other microforms. Most microforms used in libraries are service copies. Use also for microopaques. |
| m |
Mixed generation. A microform copy that is made up of a combination of generations of film. |
| u |
Unknown. The generation aspect is not known. | |
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‡j Base of film |
The base material of the image. One purpose of subfield ‡j is to determine if the microform is on a safety base film. Safety base film is a comparatively nonflammable film base that meets ANSI requirements. On some film, the phrase safety base or a small equilateral triangle appears on the edge. Some microfilm produced overseas have similar notations in foreign languages.
Vesicular and diazo microforms are always safety base, as are silver halide microforms manufactured in the United States since approximately 1951. Nitrates are not safety base films.
| a |
Safety base, undetermined. A safety base film whose type has not been identified. |
| c |
Safety base, acetate undetermined. An acetate safety base film whose exact type cannot be determined (i.e., if you do not know whether the type is diacetate or triacetate). |
| d |
Safety base, diacetate. A cellulose diacetate film base. Introduced before World War I for home movies, diacetate base was more expensive and unpredictable than nitrate base and failed to gain acceptance in professional 35 mm. film production. |
| i |
Nitrate base. A cellulose nitrate film. Cellulose nitrate support or base was used in the manufacture of 35 mm. film (and some 17.5 mm. film) until 1951. Nitrate base film is no longer manufactured. Nitrate film is highly flammable. It does not meet the ANSI requirements for safety base film. |
| m |
Mixed base, nitrate and safety. A combination of nitrate base and safety base film. The use of mixed bases, spliced together, can be found in microforms from the early 1950's. |
| n |
Not applicable. An item that does not have a film base. Such items are primarily microforms on a reflective rather than transparent base. Microopaques (also called microcards or microprints) are examples of microforms not produced on a film base. Use code n for microopaques. |
| p |
Safety base, polyester. A film base made of a synthetic resin (e.g., ester). During the 1980s, it was the most widely used base for microfilming. |
| r |
Safety base, mixed. Spliced together safety base films. Do not use if the spliced film is nitrate based. |
| t |
Safety base, triacetate. A cellulose triacetate film base. Cellulose triacetate is a high acetal compound with very low flammability and slow burning characteristics. From 1951, triacetate was used for professional and amateur produced moving image film. |
| u |
Unknown. The base of film cannot be determined. |
| z |
Other. A film base for which none of the other codes apply. | |
Printing |
Field 007 does not print. |
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