Digitization Process - Scanning & Storing the Slides:
This is a short guide describing the steps and materials needed to take glass lantern slides and: clean them for scanning, scan them into tiff and jpeg formats, and preserve them for storage afterwards.
Materials needed:
White cotton gloves
Acid free film cleaner
Professional photo wipes
3’ X 4’ sheet of fabric (fleece or velvet)
Small square of foam padding
Small horse hair brush
Acid free slide sleeves
Acid free storage boxes
Step one: Cleaning
The slides should be cleaned twice—before and after scanning—using Rexton Anti-static Film Cleaner and Premier Professional Photowipes. The first cleaning will remove long built-up dirt and grime, making the slides suitable for scanning. The second cleaning will eliminate any fingerprints, smudges or dust picked up during the scanning process.
Set up a padded work area. We purchased a yard or so of low-pile/low-lint fleece and folded it once to make a forgiving staging area for cleaning. It allows the cleaner to safely set out a few slides at a time, and protects a slide if accidentally dropped. Lay the fabric sheet out on a clean and clear work area, ideally one that will not be disturbed for a lengthy (3-4 hour) length of time.
Set the cleaner/wipes/slides on the side of the table without any fabric.
Place the square of foam padding under the fabric closest to you, this will be your work area for cleaning, this was if you slip and drop one of the slides it will not break upon impact. Wear the cotton gloves and carefully remove the first slide from its box, try to only pick it up by the edges.
Take a moment to inspect each side if the slide, noting areas with substantial amounts of dirt build up. Be warned that a certain amount of filth may be caught in between the slides of glass (dust/mold/etc.) and will be impossible to clean. With practice you will be able to tell which particles of dirt may and may not be removed. Pour a small amount of film cleaner on the photo wipe and proceed to clean the front of the slide using small circular motions. Be careful not rub too abrasively against the edges of the slides, as the tape/paper coating/labels may have deteriorated with age, thus making them brittle and easily removed. If the glass is cracked or broken be careful not to get any cleaner inside the slide. Now apply the film cleaner to an unblemished section of the photo wipe and proceed to clean the back of the slide in the same fashion.
Place the clean slide on the top left hand corner of the fabric, face down. If the slide has an accompanying tag/sheet/label place that to the slides left. Only clean as many slides in one sitting as you think you will finish scanning, that way dust will not build up on the slides overnight. If you do let them sit, brush them off before scanning. Leave the gloves on during the scanning process, so you do not dirty the slides with fingerprints and oils from your hands.
Tip: While both fleece and velvet have a similar non-abrasive surface, Fleece has a slight tendency to shed. Simply give the slides a good brushing before placing them on the scanner.
Step two: Scanning
Adjust the setting on your scanning program so that Q-Factor=1.5, Screen=400 lpi and you are scanning at 600 dpi. Give the glass and the reflective cover of the scanner a good cleaning before you start. Depending on the speed/processor of you computer, place anywhere from two to four slides down on the scanner face down. You may wish to use a ruler or other straight edge to make sure the sit perfectly square in relation to the scanner, as it is easier to do it this way than to correct the tilt in Photoshop later. Make sure the reflective cover in inside the scanner, and then select the slides with your scanning program and scan them in reflective mode. When this is complete, remove the reflective cover from the scanner, change your scan mode to transparency, and scan them again. Be very, very careful not to bump the slides when removing the cover, as this will make it very difficult to align your images later.
In Photoshop, right click the top of the reflective image and choose ‘Duplicate’, rename as appropriate and click ‘okay’. Use the crop tool to remove everything but the first slide from the image. Be sure to leave enough space on every side of the image in cause you need to rotate it to get a good picture. Now use the rectangular marquee tool to select the transparent slide on the other image. Switch to the move tool and drag the box over to your renamed file. You should now have the renamed reflective image as your background layer, with the transparent cut out above it at layer one. Now remove any remaining traces of black from around the slide image on the transparency layer. This may be done with either the magic wand tool (set the tolerance to either 40 or 50) or by using the magnetic lasso tool. If there is not enough distinction between the black and the transparent image, make a copy of the layer (right click on the layer, select ‘duplicate layer’) and choose Image/Adjustments/Brightness/Contrast and increase the brightness till there is a more apparent difference. Then delete the copied layer and use the selection on the original.
Once the transparent layer is cleaned up, zoom in to selection of the slide with a great deal of contrast, lower the opacity of the transparent layer and use the move tool to align the two layers perfectly. Flatten the image (click the arrow on the top right of the layers box and select ‘Flatten image’) and zoom back out. If the slide is crooked, change the image from a background to a layer and use free transform (ctrl+t) to adjust, and then flatten the image again. Now double click the hand tool so your image size is set to fit to screen. Save your image as a tiff file (File/Save/Change format to tiff). Then right click on the top of your image and choose ‘Image size’. Now Change resolution to 72 pixels/inch and Width/Height to your selected size. Double click the hand tool again, and resave the file (File/Save as/Change format to jpeg). Your images are now complete, remove the slides from the scanner and return them to their storage container.
Step three: Archiving
Due to handling and exposure, the slides will need to be cleaned again before being stored. Simply repeat the process described in step one.
Place the slide in an archival four-flap lantern slide envelope (acid-free, lignin-free, unbuffered). If the slide is broken or if one of the glass panes is missing, consider encapsulating it with polyester film or placing it in a comparable enclosure to protect it doubly.
Place enveloped slides in archival lantern slide boxes with 4-ply Westminster Rag Board tabbed index dividers every five slides. We used acid-free, lignin-free 4 1/2H x 4 1/2W x 10 1/2"D, boxes made from 40-point tan unbuffered barrier board. They can house about 50 slides per box (including dividers) and have deep lids.
We labeled every box, divider and slide envelope with acid-free foil-back labels. Individual slide labels showed call number, collection name, library name, slide number and slide title. Divider labels showed the numbers of the five slides after the divider. Box labels showed call number, collection name and date range, box number, and slide numbers contained therein.
Step four: Completion
Finished! Congratulations!
Photographs
Old Box – New Box The Mira Lloyd Dock Forestry Slide Collection was previously housed in a variety of old wooden boxes shown here alongside an archival glass lantern slide box.
Four-flap with Polyester Film Close-up of glass lantern slide in four-flap enclosure. This particular slide was missing one of its glass panes—leaving sharp edges exposed—so it was encapsulated in polyester film as extra protection against slide breakage (and bodily harm!).
New Box with Labels Archival lantern slide box showing box labels, divider labels, and individual slide envelope labels. Also pictured are the anti-static film cleaner and photowipes.
All Boxes with Supplies Cleaning and re-housing finished: ten boxes, 468 slides