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- Specifications
- Preparation and Targeting
- Shipment Receipt
- Materials Handling
- Filming
- Equipment
- Testing
- Materials
- Microfilming Methods & Procedures
- Targeting
- Image Placement
- Material Dependent Requirements
- Processing
- Quality Control
- Duplication
- Polysulfide Toning (All Films)
- Labeling, Packing & Shipping
- Per Customer Request
- Research Libraries Group. RLG Preservation Microfilming Handbook. Mountain View, CA, 1992.
- Research Libraries Group. RLG Archives Microfilming Manual. Mountain View, CA, 1994.
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Document Preparation
Preservation Microfilming Standards, Guidelines, and Specifications adhered to by Heritage Archives |
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- Specifications
The preservation microfilming production procedures and systems at Heritage are based on strict adherence to the
specifications, guidelines, and standards from the American National Standards Institute (ANSI), the Library of Congress (LOC),
and Research Libraries Group (RLG). All Heritage projects are exclusively preservation microfilm projects. We do not accept
microfilm projects that are commercial in nature or intended as bulk reduction work. All our staff training and daily focus is
on creating microfilm that will last for the full 500 year Life Expectancy (LE) of preservation microfilm.
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- Preparation and Targeting
- Shipment Receipt
Upon arrival of each shipment Heritage will inventory each box to ensure that the material has arrived undamaged
and that the content matches the packing list. We request the Library send a packing list (with insurance values
included for volumes) with each shipment so that our staff can annotate the condition and inventory and return a
copy to the Library for their records. We understand the each shipment to Heritage is to be returned to the
library as a unique shipment with the microfilm for library inspection.
- Materials Handling
All incoming shipments are held in our pre-filming area together on a wooden pallet. Each shipment is clearly
identified with our Project Workorder packet. Cleanliness and orderliness are carefully emphasized. Our entire
facility is a smoke free building.
The pre-filming and post-filming storage areas are climate controlled with air-conditioning and forced air
heating that maintain the area at or around 70 degrees year around. All shelving is at least 4" above the
floor and all boxes of materials are stored on pallets prior to shelving or shipment. Camera technicians
assigned to film your project take material to the filming area one reel at a time and return the material
to a post-filming pallet for your project after filming. In this way your materials are always together and
clearly labeled. We handle each shipment as a separate work order and return materials, master microfilm, and
duplicates at the completion of each shipment along with a complete invoice for that shipment. This allows
you to track progress against your budget or purchase order on a timely basis.
Should any material be received that in our opinion cannot be filmed without damage to the binding and/or text
our preservation microfilming project manager will be notified and the material set aside pending client decision.
All bound materials will be microfilmed using the appropriate book cradle.
Materials will be handled with clean hands in a clean, dust free work area. If the material itself contains ink
that rubs off or has a high acid content microfilming staff will wear cotton gloves to protect themselves and
the material. No extraneous materials will be introduced into the materials by Heritage staff: paper clips,
rubber bands, targets, or sticky notes will not be used.
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- Filming
- Equipment
Heritage uses only high quality cameras to produce 35mm preservation microfilm. Our fourteen (14) cameras
consist of 7 MRD-II's, 2 MRC's, and 5 MRG's. Every one of these camera meets or exceeds all ANSI/AIIM or
RLG specs for resolution at every reduction ratio. They substantially exceed the resolution quality test
score required by your microfilming project.
Every microfilm technician is equipped with a hand-held Minolta Spot Meter that is used to measure reflected
light intensity very accurately. Technicians use the Spot Meter during filming any time they perceive a
change in the color of the material that might create a change in the density of the camera master film.
The operators then vary the light voltage on the camera to maintain a constant density on the master film.
It is our experience that automatic reflectance densitometers that tie directly to the camera are less
accurate than this manual Spot Meter approach. The automatic reflectance densitometers cannot be aimed at
areas that do not contain text. (The Minolta Spot Meters need only ½ inch of space without text or image
for the operator to get a reading from this spot, thus their name "Spot Meter".) Any material that contains
photos or illustrations or heavy, large text will cause the automatic reflectance densitometers make
inaccurate adjustments to increase light and increase density on that shot in an undesirable manner. We
have disconnected all automatic reflectance densitometers in favor of our system which relies on human
judgement aided with the best light reflectance measurement devices available.
- Testing
Each workday morning before 7 am we inspect the prior day's production of every master reel of microfilm
for density, resolution, and uniform density by an experienced laboratory technician. If any problems exist
filming is halted on that camera and a supervisor notified so the camera can have the necessary adjustments
made and the camera can be retested before resuming production.
To verify uniform illumination a blank sheet of white paper 24" x 36" is filmed with the blade masks wide open
and the camera head positioned at a 20X reduction ratio. After the test has been processed, density readings
are taken across the frame. If the difference between the highest and lowest density measured exceeds .20,
the camera lights are adjusted or replaced and the camera retested and proven to be in spec before filming is
resumed. The .20 density variation maximum on a 24" x 36" inch document is much harder to achieve than the .10
density variation maximum on an 8 ½" x 11" that some others use because the curvature of the camera lens makes
it difficult to achieve even illumination towards the corners of such a large paper.
Focus test results for every camera are logged on the Production Work Order produced for every master microfilm
reel produced. The score must meet or exceed the minimum ANSI/AIIM standard for that reduction ratio or the reel
is refilmed and the camera is adjusted. If adjustment is necessary a technical target is filmed at the camera's
current focus setting and also at settings immediately above and below the current setting. After processing, the
technical target is read with a 100x microscope to determine the focus setting that achieves the maximum possible
resolution. This text is first performed at 21X. Once set, the test is then repeated at 7X, 12X, and 16X to verify
that the adjustment has not reduced focus at any other reduction ratio and that focus at all reduction ratios meets
or exceeds national standards. Once a camera is in focus it is likely that it will remain in focus for years, until
or unless something breaks or loosens.
Achieving consistent densities in the appropriate range for the material being microfilmed is crucial to producing
preservation microfilm. It is the maintenance of this parameter that requires more time, attention, and refilming
than all others combined. To ensure that densities both within a title and across a reel of microfilm remain as
consistent as possible density tests are performed prior to filming every project. Each type of material and color
of paper is tested to determine the optimum Minolta Spot Meter reading for the particular camera on which the
material will be filmed (each is slightly different due to camera differences). Each material will be shot at 10
different light intensities, 5 lighter than the anticipated set point and 5 darker than the anticipated set point
at the same reduction ratio as the material will be microfilmed (density changes as reduction ratio changes on the
same material shot on the same camera). The Heritage lab then signs off on the correct Minolta Spot Meter reading
for each material before the microfilm technician begins microfilming that material.
Once Minolta Spot Meter settings are signed off by the lab the technician will shoot one reel of film. The
technician will then return to filming another project and await the lab results from the following morning's
inspection before proceeding with filming. (All master reels are held overnight to allow at least 12 hours time
to pass prior to processing so that latent image fading will not create darker images toward the end of a reel
than at the beginning of the reel.) The laboratory technician inspects the master film to make sure there are no
camera and/or processor problems that have occurred. The resolution technical target is read at the start and at
the end of the reel to ensure the camera is achieving resolution that meets ANSI specs. Density readings are taken
both of the uniform density target and on the original material images to ensure density on all images is within
the specified target density range for the material being microfilmed. It is not uncommon for 15 or 20 density
readings to be made on a reel. Refilming of a dark or light page is common. Splices in a master reel never exceed
the allowed 6 splices for any reason.
- Testing
35mm AHU microfilm or the equivalent is the 35mm camera master negative microfilm used by
Heritage. All negative silver duplicates are 2468 or 2470 or the equivalent 4 mil thickness microfilm. All
films meet the latest version of ANSI IT9.1.
- Microfilming Methods & Procedures
- Targeting
All targets are shot at 12X. The size of the "START" and "END" targets on microfilm are at least 2 mm high.
The resolution target is shot at the same reduction ratio as that used on the original material. When we are
filming more than one title on a reel the complete start and end target sequence will be used on each title
with 4" to 12" of clear space between end and start targets. The density on all targets will be 1.0 to 1.3.
The density variation on the uniform density target will not exceed .20 total variation from the highest to
the lowest reading.
- Image Placement
Once the camera operation is fully tested filming will begin. Filming will be one or two pages per exposure
with no skew beyond 5% from parallel with the longitudinal axis of the film. Each page or pages will be
centered within the exposure in both directions. Interframe spacing will be regular and consistent and
variations will not exceed 50% of the average interframe distance. There will be no overlapping exposures.
Spacing between titles/volumes will not be less than 4 inches or more than 12 inches, unless otherwise
directed. On an MRD/MRC camera the operator will advance the film 3 cranks, on an MRG camera the operator
will advance the film 8 spaces between titles/volumes.
The reduction ratio used will be the one that approximately fills the image area across the width of the
film but will not be lower than 8X. All document edges will be visible in the image. The reduction ratio
will not change within one title on one reel of film. If there is more than one title on a reel the
different titles may have different reduction ratios. Heritage will follow all directions given by the
client when determing reduction ratios and image orientation.
- Material Dependent Requirements
Covers, endpapers, and all pages are filmed, including blank pages or backs of pages that figure in
consecutive pagination whether actually numbered or not. Blank pages that do not figure in pagination
are not filmed.
Folded maps, charts, or illustrations that are larger than the text pages will be filmed in the sequence
in which they appear within the text. Foldouts that are too large to fit into a single frame and still
be legible will first be filmed as a whole, and then in sections at the original reduction ratio from
left to right and from top to bottom. An overlap of at least one inch will be left between contiguous frames.
Pages with missing material (holes in the page) will be backed up with white paper prior to making the exposure.
Intentional duplicate exposures will be taken at the microfilm technician's discretion to optimize the
legibility or to compensate for large variations in paper fade or ink intensity or color within a single
frame. Intentional duplicate exposures will be taken where color or halftone variations in the same frame
need widely differing exposure settings to achieve optimal image capture. The need for excessive duplicate
exposures may indicate the need for single page, rather than double page, exposures. In this case the
material will be set aside and the client contacted for approval before this change is made.
- Processing
Once filming is completed on a master reel it is held overnight prior to processing to allow latent image
fading to even out across the entire length of the reel. The filmed material is returned to the filmed
area of materials storage to await inspection of the master by the laboratory technicians and completion of
that entire shipment.
Exposed microfilm will be processed and examined during spool down from the 2,000 foot processing reels
onto which camera master negative microfilm is accumulated for processing. This examination will identify
any gross camera or processing problems or scratches that need immediate attention. At this time density
readings are taken and appropriate resolution is verified. Both are noted on the Production Worksheet
for the reel.
All masters are free from scratches, emulsion or base holes or tears, finger marks, chemical residues or
splash marks or any other defect that might affect the quality, lifespan, or legibility of the images.
Each day that Heritage processes microfilm we perform a Methylene Blue test to assure residual thiosulfate a
nd residual polysulfide toning compounds are well below allowed maximums for LE 500 microfilm. Each day
that Heritage processes we perform a silver to silver sulfide conversion test to determine that the minimum
conversion is 40% or more. Our average conversion is 80%. Each month Heritage's Methylene
Blue testing procedures are validated to ensure that the tests conducted by Heritage are valid.
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- Quality Control
The film processing room and Quality Assurance Laboratory are connected. After processing the master microfilm is
spooled down by an experienced Lab Technician and inspected. All QA results will be recorded on client specified or
supplied forms, including original defects and steps taken for correction. The applicable QA forms will be returned
with each return shipment of master microfilm, original materials, and an invoice for that shipment.
The first QA examination is for density. A minimum of five readings per reel or three per title will be taken.
Density variance within any reel will not exceed more than .20 densitometer points. Allowable density ranges for
high contrast material is 1.0 - 1.3; for medium contrast material is .9 - 1.1; and for low contrast material .8-1.0.
Minimum background density readings will not exceed .10, and are normally .03 to .05. When a reel fails to fall
within the acceptable range for the material being filmed or if the density range is too variable the material
will be refilmed. In some cases refilming of a portion of a reel will resolve the problem.
Resolution will be measured with a 100x microscope to ensure that it is within minimum tolerances. The film is
first checked to make sure the resolution meets the basic minimum ANSI standard for resolution at the indicated
reduction ratio. This test ensures the camera is operating correctly. Then the Quality Index rating is
calculated using the height of a letter "e" for the material being filmed. First, second, and third generation films
will all have a Quality Index Rating of 8.0 or higher or the material will be refilmed (or reduplicated). For
newspapers, we will continue to adhere to the ANSI standard for newspapers that define the minimum resolution of
5.6 at 20X and will not calculate the Quality Index.
For non-daily newspaper projects, upon passing all other QA inspections a page by page inspection of the
film will be performed. We anticipate expanding page by page inspection during the coming year to include
ALL masters. We create an inexpensive vesicular duplicate for this inspection to ensure there is no chance
of scratching an otherwise perfect master copy. This vesicular copy is discarded after page by page
inspection or used for a customer service copy if the master is error free and a subscriber receives
vesicular film. Any missing pages or accidental double exposures will be eliminated by refilming or
splicing prior to the creation of second or third generation reels. No master negative will have more than
six splices. No second or third generation duplicates will have splices. All splicing is performed with
ultrasonic splicers.
Master and print master films are handled only by technicians wearing cotton gloves.
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- Duplication
Prior to duplication all masters will have passed final QA inspection as described above.
Duplication instructions are contained in the Work Order packet that accompanies each shipment to the Lab.
Print Master film normally is Direct Duplicating film type 2470, but type 2468 will be used for
material that is strictly black on white text with high contrast, or by customer preference. For service
copies Duplicating Microfilm, type 2462 will be used (extremely fine grain, medium contrast, blue
sensitive, polyester based gelatin film) in 4 mil thickness.
The film will be processed (which includes polysulfide toning of all duplicates as well as masters)
and then sent to QA to be spooled down onto 100 foot reels for film inspection. Print master minimum
density will be between .15 and .25 for 2470 film and .08 and .12 for 2468 film. Service copy maximum
density will be between .95 and 1.25 and minimum density will be less than .15. Density readings will
be reported on the QA form. There will be no splices in the print masters or service copies.
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- Polysulfide Toning (All Films)
Heritage performs polysulfide treatment (brown toning) of all silver microfilms we produce using
Brown Toner. Our polysulfiding treatment and results meet all guidelines developed by the Image Permanence
Institute. Polysulfide treatment is highly recommended by the Research Libraries Group. Polysulfide
treatment does not repair film that has degraded from oxidative attack but it does effectively stop
oxidative attack from continuing. However, polysulfide toning of film that has some redox can result
in the film appearing even more damaged than prior to treatment as the polysulfide toning will eliminate
the oxidized silver that was still blocking light and contributing to the appearance of the image.
Generally film that has redox is old enough that it is acetate based film. In this case the recommended
course of action is duplication onto polyester based film that is then polysulfide toned. Silver sulfide
is hundreds of times more stable than silver to the effects of atmospheric pollutants encountered during
long term storage, regardless of the environment in which the film is stored.
A sample of polysulfide treated film is tested in-house for silver conversion to silver sulfide each day
we process. We achieve average conversion of 80% silver to silver sulfide using the dichromate bleach
test. We test a film sample daily using the peroxide immersion test to ensure the polysulfide toning
mixture has not begun to produce unwanted red hues in the film clear areas due to exhaustion or oxidation
of the polysulfide toning chemistry.
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- Labeling, Packing & Shipping
Once QA tests are completed each reel will be wound with the START target on the outside of a chemically
inert plastic reel, fastened with an acid-free button and string tie, placed in acid and lignin free box
of the proper dimensions and thickness, and the appropriate label applied.
Labels will be produced on acid-free label stock for each reel of film. Heritage uses a standard label
format that will include the following information, depending on the project type:
- Newspapers-Masthead Title, Place of Publication, and Date Range.
- Serials-Title, Volume/Issue Range, and Date Range.
- Single Monograph-Title.
- Multiple Monographs-Project Title (If requested) and Titles in the order they appear on the film.
- Manuscripts-Collection Title, Series Number or Date Range, Box/Folder Range.
Heritage can provide specialized label formats upon request. Please supply us with a copy of the desired
format. There is no additional charge.
All completed masters and duplicates are sent to a final check station where they are matched to the packing
slip and invoice that have been created. The packing slip and QA paper work are included with each shipment.
Masters and original material are always returned as separate shipments. Duplicates are generally shipped
with the original material.
Labeling: The storage number, title of the serial filmed on each reel, and the film generation (1N, 2N, 3N)
shall be written in pencil on the corresponding boxes of film for all three generations of microfilm. The
storage number for each title shall also be written on a quality control form for that title. This will enable
the Library to match the correct original volumes with the appropriate reels.
Shipping: Materials and film will be shipped via UPS or UPS Freight Logistics unless otherwise specified by the client.
Materials received as one shipment will be returned as one shipment. Exceptions may be made with the prior agreement of the client. Volumes
filmed as a reel will be tied together with a string.
Masters are always returned separately from original material and/or duplicates to the customer if the masters are not stored in our vault.
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Document Preparation
The following is Heritage's definition of camera-ready:
- Each item will be inspected page-by-page for anomalies and paper strips with instructional information (flags)
will be inserted for "required as needed" targets/instructions given to the camera technician. For example - missing
issues or missing or damaged pages should be flagged.
- Any irregularities in pagination will be noted and flagged. If the text is incomplete targeting and/or filming
instructions will be prepared and inserted in the item.
- If any text is obscured (for example, by tape, markers, or staining) it will be noted and appropriate targeting
instructions prepared and inserted in the item.
- If issues or pages are bound incorrectly, filming instructions will be prepared in order to correct what
amounts to a binder's error. These instructions will be inserted in the volume. Alternatively, if issues are to be
filmed as they are bound, this instruction will be given so that a condition target stating "Filmed as Bound"
can be filmed at the beginning of each reel.
- If other special features require special filming attention, instructions will be prepared and inserted in the
item. If the condition requires targeting, that also will be noted for the targeting process. Examples of special
features may include foldouts, color illustrations, or airmail letters.
- Material that cannot be filmed as bound will be disbound and/or threads loosened as needed - with the
written permission of the client. A general rule will be made at the beginning of each project whether:
- All items may be disbound.
- Only specific items may be disbound.
- No items may be disbound - without permission in writing from the client.
- Reel breaks and master negative storage numbers will be assigned. In other words, the material to be
filmed on each reel will be determined, and each reel will be assigned a unique number.
- All bibliographic targets will accompany each reel, unfolded and in separate folders or envelopes
marked with the master negative number.
- All volumes/folders will be put in the order to be filmed.
- Materials will be flattened and staples or clips removed and any extraneous material removed.
Standard filming targets, such as START, resolution charts, and END targets, and in-frame as-needed targets,
such as "Damaged Pages" or "Irregular Pagination" in-frame targets will be provided by Heritage.
These instructions are meant to serve as a general outline. Any additional make-ready necessary by Heritage
will be charged at $17.90 per hour.
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Preservation Microfilming Standards, Guidelines, and Specifications adhered to by Heritage Archives
American National Recommended Practice for Inspection of Stored Silver Gelatin Microforms for Evidence of Deterioration. ANSI/AIIM MS 45-1990.
American National Recommended Practice for Microfilming Printed Newspapers on 35mm Roll Microfilm. ANSI/AIIM 111-1994.
American National Recommended Practice for Operational Procedures/Inspection and Quality Control of Duplicate Microforms of Documents and from COM. ANSI/AIIM MS 23 -1998.
American National Recommended Practice for Operational Procedures/Production, Inspection and Quality Assurance of First-Generation Silver Microforms of Documents. ANSI/AIIM MS 23-1998.
American National Standard - Micrographics, Splices for Imaged Microfilm - Dimensions and Operational Constraints. ANSI/AIIM MS 18-1992.
American National Standard for Photography (Chemicals) - Residual Thiosulfate and Other Chemicals in Films, Plates, and Papers - Determination and Measurements. ANSI/PH 4.8 - 1985.
Photography - Determination of residual thiosulfate and other related chemicals in processed photographic materials - Methods using idodine-amylose, methylene blue and silver sulfide. ISO 18917:1999.
American National Standard for Imaging Media - Processed Safety Film. ANSI/PIMA IT 9.11 - 1998.
American National Standard for Imaging Media (Film) - Silver-Gelatin Type - Specifications for Stability. ANSI/NAPM IT 9.1 - 1996.
American National Standard for Media (Film) - Photographic Processed Films, Plates, and Plates - Filing Enclosures and Storage Containers. ANSI/PIMA IT 9.2 - 1998.
American National Standard for Imaging Materials - Methods for the Evaluation of the Effectiveness of Chemical Conversion of Silver Images Against Oxidation. ANSI/NAPM IT i.15 - 1993.
American National Standard for Micrographics - Microfiche. ANSI/AIIM MS 5 -1992. (R1998).
American National Standard Dimensions for 100 Foot Reels for Conventionally Threaded Processed 16mm and 35mm Microfilm. ANSI/AIIM MS 34 - 1990.
American National Standard Specification for Imaging Materials - Photographic Films - Specification for Safety Film. ANSI/NAPM IT 9.6 - 1991. (R1996).
Eye-Legible Information on Microfilm Leaders and Trailers and on Containers of Processed Microfilm on Open Reels. ANSI/NISO Z39.62-2000.
Photography - Processed photographic materials - Photographic activity test for enclosure materials. ISO 14523:1999.
International Standard for Photography - Determination of Residual Thiosulfate and Other Related Chemicals in Processed Photographic Materials - Methods Using Iodine-amylose, Methylene Blue and Silver Sulfide. Geneva, Switzerland: International Organization for Standards, 1999.
Research Libraries Group. RLG Preservation Microfilming Handbook. Mountain View, CA, 1992.
Research Libraries Group. RLG Archives Microfilming Manual. Mountain View, CA, 1994.
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