From microfilm to microsheets - the evolution of the microform
At first, it was magnetic tapes and floppy disks that made us believe we had a reliable memory. After that, CD-ROMs swelt us in apparent safety. Since then, further innovations convey the illusion that digital data can be secured in a stable way from now on. Glass and ceramics are actually very promising.
They all do not reduce the main risk of digital data storage - the demanding coding and the compulsion to keep complicated reading technology available. Therefore, since the beginning of digitization, the additional storage of analog images of all those data that can be visualized has nevertheless been favored. Already in the 1980s, there was a technology with the COM film adaptation to transfer screen content to microfilm. Later methods increased the resolution significantly, the microfilm remained mostly monochrome. Since 2007, archium itself, in conjunction with the Fraunhofer Institute for Physical Measurement Technology, the company Media de Lux in Offenburg and state partners such as the Landesarchiv Baden-Württemberg and the Institute for the Preservation of Archive and Library Material, has been involved in the development of a method for securing digital content on high-resolution microfilm in color. The technology was able to expose 3µm of small colorful laser spots on 35 mm microfilm of Ilfochrom-/Cibachrom and is still unsurpassed in the microfilming segment.
But the film adaptation itself also has a fundamental problem, which is why it is now - unfortunately - on the verge of extinction: Both the production of microfilm and the film development are based on very demanding, health-endangering and expensive chemical processes. Only black and white or grayscale microfilms are still reasonably economically available.
The changed user behavior is also of great importance. In the past, almost every library had workstations with special microfilm readers. In each workshop there were small carousels for Fiche resp. Microfiche - a kind of microfilm in postcard format - in which the masters could retrieve their parts lists and production details. They also needed special readers for this, which optically enlarged the analog-reduced image to screen size. These operations are now completely taken over by computers and have become completely obsolete. However, this eliminates the main areas of application for analog readers. Therefore, readers that are able to digitize analog microforms are in demand on the market today. These devices are expensive and the quality of these scanners is mediocre, which is why such devices occupy only a market niche and are far from being found in any office.
archium therefore went in search of a microform that is durable, allows a similarly good writing density as microfilm, is inexpensive and - this is actually even the most important thing today - can be immediately re-digitized everywhere with available means. Our process for combining image with metadata, for processing for easier digital reuse, the optimized data preparation for spot-accurate image reproduction and the raster-free printing technology make it - admittedly very high-quality paper - microsheets.
In contrast to SW microfilms, the microsheets of archium are colored. However, if the customer prefers grayscale prints, we can use our arCODECO method to sequentially image and reassemble RGB and CMYK color channels. For the preservation of authentic color impressions, this process is even more reliable than those processes that transform color spaces - as is basically the case with color printing!
With the overlapping laser spots we achieved an actual resolution of approx. 100 line pairs per millimeter in an image segment of 35x49 mm. On the microsheets we currently achieve a resolution of 22 line pairs per millimeter. However, the total area available to us is much larger, so that in practice we achieve a greater usable data density per microsheet. Our microsheets can be manufactured up to DIN A3 format, DIN A4 is our standard.
One more comment on the storage density of microfilm in terms of volume. A roll of 35 mm microfilm contains 600 frames. This corresponds to 1,200 document pages for 2 documents per frame. Six boxes of microfilms have about the volume of a phone book. This therefore results in a storage density of about 7,200 silks DIN A4. Compared to the archium microsheets, 20,000 pages can be printed on 500 sheets of paper. Accordingly, microsheets have about 3 times the storage density of microfilm and can also be printed and archived in color with a table of contents. Seen in this way, microsheets are a serious alternative to the well-known microfilm.
