Tuesday, May 17, 2016

Image Resolution and You

Picking your resolution is perhaps the most important decision you'll make when digitizing photos, artwork, or any other kind of image. But it can also be confusing if you're not familiar with these terms and their meanings. This is a simple primer to help you choose the right resolution for your needs.

The terms DPI and PPI are both shorthand units for measuring an image's resolution. DPI stands for "dots per inch" and PPI, "pixels per inch." This means that DPI is technically a term for a printed object's resolution while PPI describes an image displayed on a screen, but in common use they are essentially interchangeable.

The system that these measurements describe is called Raster, and it's by far the most common in a modern digital setting. A raster image is essentially a mosaic, collecting dots of color called pixels in a tiny square grid to produce an overall image. The more pixels per inch, the more detailed the image. Simple enough, right? For an easy example, here is the same image at three different standard resolutions: 600dpi, 300dpi, and 72dpi (click to see at full size)

You can always lower the resolution of an image, but it's impossible to raise it, except in a simple multiplying sense. This is why all digital images look blurry if you zoom in far enough. You're making the pixels bigger, but you aren't adding any new information to them.

Another factor you will want to consider is your display resolution. Modern high-definition TVs will often give you this basic measurement, and while computers have a greater variety of resolutions they will generally fall under a few typical values. 480p means a screen is 480 pixels wide, and is considered "standard" definition. 720p is, of course, 720 pixels wide, and marks the beginning of "HD" standards. 1080p is probably the most commonly used HD resolution, and the cutting-edge "4K" resolution is a convenient shorthand for screens 3,840 pixels wide. The screen resolution will determine how "large any given image looks at full-resolution on the screen. If you try to stretch a 480p wide image across 1080 pixels, it will look bad.

While the ideas surrounding pixel resolution, display resolution, and print resolution are quite complicated, they can still be understood easily with a few guidelines. For most purposes you can create images using 3 different resolutions:

600ppi is what we at the Dartmouth Digital Library Program use as the standard for high quality "master" images. Although many scanners can go higher, the size of the file becomes very unwieldy at that point. My advice is to always start at at least 600. Better to have a high-quality image and not need it than to need it and not have it.

300ppi is a common resolution for a high-quality print. Unlike looking at a screen where the resolution can be shrunk or blown up, a printer is rigidly limited in the amount of detail it can put into any given area. While a particularly good printer may get higher resolutions, most will clock in around 300dpi. This lower resolution also makes transferring files for print easier. And of course, it's always useful to keep your higher-res files around in case you need to go back to them.

72ppi has become the most common display resolution on the internet. There are a few things to consider before simply converting your image into 72ppi. Look at your display, and understand what its resolution is. Then consider how "big" you want your image to look on the display. So, if you have a 1080p monitor and want an image that fills the whole screen, you'll want to change your ppi to 72, AND change your image width to 1080p at the same time, with the proportions locked.

Here we can see Photoshop's image size menu (Image -> Image Size), where the pixel width and resolution are changed while the proportions remain constrained.

This is often a confusing concept to grasp. The simplest way I can think of is: if you reduce a 300ppi image to 150ppi, but also double its size, it will essentially be the same image when you see it on your computer. But if you try to print that, it will be half as detailed by virtue of being twice as big.

Fortunately, you don't need to fully understand all of this in order to create and work with high-quality images. As long as you make sure your highest-quality 600ppi master versions are safely backed up, you can play around with these variables in Photoshop or any other imaging program until you meet your own needs. Understanding how screen resolution, print resolution, and image resolution work together is an ongoing process that changes with technology as well as peoples' needs. It's important to be consistent, especially so for an institution like ours, but it's equally important to know how to adapt to your own needs.

Written by Ryland Ianelli

Tuesday, May 3, 2016

Conserving Collaborators: making it work.

Last October, I had the pleasure of having Giselle Simon, Head of Conservation at the University of Iowa, in the lab for a day.  Giselle and I go way way back so it was just like old times.  I thought "What could we do in a day?"  I recalled that Giselle had treated many antiphonals when she was the Conservator at the Newberry Library in Chicago.  And it just so happens that we have one here that is displayed in the reading room of Rauner Special Collections in need of assessment and attention.  So how perfect, with Giselle's help (which this was definitely a two person job) we transported the antiphonal down the long corridors and elevator rides to the conservation lab.

All tied up and ready to go.  Rauner Special Collections reading room.

Being able to maneuver the pathway was tricky.

Getting the book into the elevator.  Tight squeeze.

Riding solo going down, no people allowed.

Once off the elevator, transport got a bit easier as we had a truck to put the book on and wheel away.

The goals for the day were simple.  To assess the book, perform some minor stabilization, and create a carrying/support tray.

Giselle using a HEPA vacuum to clean soiled surface.

Once we got the book situated, we realized that the surface needed quite a bit of cleaning.  Surface debris was evident in a substantial amount of areas.  Giselle hopped right in and gave it a go with her gentle touch.

In the paste down area there was extra surface debris which she was able to clean.

The back board was damaged at the fore edge, missing the outer portion of the board.  This resulted in the pages bending at the fore edge because there was no support under them.  Therefore we came up with a quick solution for a moderate fix.  We cut a strip of matt board that fitted precisely into the missing area and pasted it down with a tissue strip placed in top for a bit of extra strength.

Piece of matt board secured to fore edge of lower board.

 The next step was to fabricate a carrying tray.  We didn't have all the materials to make one like the Newberry so we improvised.

Carrying tray at the Newberry.  Coroplast lined with Volara.

Newberry tray showing a catch wall at the back.

Nothing like getting out the glue gun.  I knew I had bought that for something!

Multiple layers of blue corrugated board were laminated together to make the tray, then we adhered a sheet of Volara.  We also had time to relax and flatten some of the pages.  So in a few hours a lot was accomplished.  The antiphonal was returned at the end of the day in much better shape than it had been.  Because of the detailed inspection and keen team work the next steps are within reach and a game plan is laid.  Sometimes, those seemingly overwhelming big jobs, just need that initial step, and having a conserving collaborator around can be just the thing.

I've always fantasied about a conservator exchange program, whereby we could visit each other's labs to help on a project, to share our experiences, and to learn new techniques and approaches.  A week would be great, but I'll take a day!  Thanks Giselle.

Giselle, settling in!

Written by Deborah Howe

Tuesday, April 19, 2016

Preservation Week Webinars

Preservation Week is an annual celebration hosted by the American Libraries Association, Association for Library Collections & Technical Services, Preservation and Reformatting Section. This year there are two free webinars that may be of interest to the public as well as preservation professionals:

From Cassette to Cloud: Reformatting Audiotape
Tuesday, April 26, 2016
Webinar begins at 2pm Eastern, 1 pm Central, noon Mountain, and 11 am Pacific
Krista White, Digital Humanities Librarian, Rutgers University-Newark
Oral histories can provide a wealth of information about individual and community life. This
webinar explores ways these recordings can be digitized, and the challenges in doing so.

For additional information and access to the free registration links, please go to the following website: http://www.ala.org/alcts/confevents/upcoming/webinar/042616

Preserving Your Digital Life
Thursday, April 28, 2016
Webinar begins at 2pm Eastern, 1 pm Central, noon Mountain, and 11 am Pacific
Krista White, Digital Humanities Librarian, Rutgers University-Newark
Many of us record and keep personal and family stories in digital formats. This webinar explores steps to take now to for preserving these narratives for future generations. means considering how we create the files and how we store them. What steps can we take now to make the ensure the best possibility of retaining these important files into the future?

For additional information and access to free registration links, please go to the following website: http://www.ala.org/alcts/confevents/upcoming/webinar/042816

These webinars are primarily intended or individuals, but will also be of interest to local historical societies and other cultural heritage groups.

ALCTS webinars are recorded and registrants receive a link to the recording shortly following the live event.

Thanks to ALCTS Continuing Education Committee for providing this information.

For more information about Preservation Week go to: http://www.ala.org/alcts/preservationweek

Tuesday, April 5, 2016


Thursday and Friday April 7 & 8, 10:00-5:00
Book Arts Workshop, Baker Library

Come print with Amos Kennedy! On Thursday, April 7 & 8, world-renowned letterpress artist Amos Kennedy brings his unique vision and hands-on approach to the Dartmouth community with an all-day, drop-in workshop held in Dartmouth Library’s Book Arts Workshop. Kennedy, the subject of documentary film "Proceed and Be Bold!”, is a self-proclaimed “humble negro printer” whose work raises raises profound questions about race and individuality. Come make a poster, check out the presses, and chat about art, printing, and Kennedy’s new project: the Detroit Printing Plant. 

This Dartmouth community event is sponsored by the Dartmouth Center for the Advancement of Learning (DCAL), the Neukom Institute for Computational Science, and the Dartmouth Library’s Book Arts Workshop.

Tuesday, March 22, 2016


Every day my in-box has several notices about the hottest digital preservation blog post, current trends in library services, or think pieces.  Most days I give them a quick scan perhaps setting a couple aside for closer reading.  Here are a few items worth a second look:

Digital Preservation Handbook, revised 2nd edition:
This was a fantastic resource when it was published in 2001 (the decision tree was my favorite part) and the update looks even better. With new case studies, video clips, recommended technology it is in a soft launch with more sections being added and revised.  Bookmark it -- you'll go back again and again.

Digital Preservation Matters:
Chris Erickson's blog summarizes news articles and reports about the work of digital preservation. Subscribe if you haven't already; something new and thought provoking every time.

NMC Horizon Repor: 2016 Higher Education Edition:
Ya' gotta read it so you won't be surprised when the predictions are played out in your library. Interesting organization of solvable, difficult, and wicked difficult problems.  Is augmented reality coming to a library near you?  In 2-3 years it will be!

HathiTrust Print Monograph Archive Planning Task Force Final Report:
I love it!  Deep thinking into creating a monographic print archive.  The report is a broad outline of how a monographic print archive can be built on the strength of the existing digital collection contained in HathiTrust, the guiding principles, and challenges to create it.  If you love collection management (seriously, who doesn't?) it's fun to read the considerations and framework for an ambitious multi-phased project.

What Google Learned From Its Quest to Build the Perfect Team (Charles Duhigg, New York Times Magazine)
As librarians we collaborate and spend time in project & committee meetings.  Why are some committees and teams more effective than others?  Google threw their resources into solving that question and discovered what some have known all along: "In the best teams, members listen to one another and show sensitivity to feelings and needs."

Enjoy reading!

Written by Barb Sagraves

Tuesday, March 8, 2016

Digital Production Unit Update

Last fall the Digital Production Unit purchased some photographic equipment to supplement our growing production output.  We have identified a need for more portable camera setup that can also give us the ability to shoot larger items.

The camera equipment includes:
Canon EOS 7D Mark II DSLR Camera (Body Only)
Canon EF-S 60mm f/2.8 Macro USM Lens
Canon Speedlite 600EX-RT Two Flash Wireless Portrait Kit

Other supporting equipment includes:

Oben AC-1451 4-Section Aluminum Tripod with PD-117
Manfrotto Auto Pole- A set of Two Black -1382956
Manfrotto Super Clamp W/Standard Stud -1382900
Manfrotto U Hook Crossbar Holder-1382902P
Manfrotto Telescopic Crossbar
Manfrotto 032BASEB Single Base for Autopole, Black

This setup gives us much more flexibility to shoot in other locations in the library when materials may not be as portable as the camera equipment.  We have also been looking for a way to shoot materials like maps or posters that are too large for the copy stand on our reprographic system.  This will give us a solution to that problem.  As always, if you would like more information about the Digital Production Unit or if you would like to visit Baker Rm.2 and see our setup, please contact Bill Ghezzi or Ryland Ianelli.

Written by Bill Ghezzi

Tuesday, February 23, 2016

Samplings of Student Work in the Book Arts Workshop, part 2

In part 1 of Samplings of Student Work in the Book Arts Workshop we saw the finished product of many projects.  Here are some photos of the work as it was happening.

Mallory Byrd '19 made this great transparent book for the course, Collage: Bridging the Gap, photo 1 

Mallory Byrd, photo 2

 Mallory Byrd, photo 3

 Jordan Craig '15 and Isaac Smith '15 made awesome books for Studio Art Senior Seminar.

 Here's another shot of Jordan Craig's Senior Seminar books using the Coptic style binding.

 Carly Schnitzler '16 punches out all the vowels in her letterpress printed book.

 Kassaundra Amann '16 used leaves and bark to create her plates for pressure printing the pages to her book, photo 1

 Kassaundra Amann, photo 2

 Marie Schwalbe '16 needed a range of purple paper so she printed it on the Vandercook!  Photo 1

Marie Schwalbe '16, photo 2

 Carly Schnitzler '16 at it again, setting and printing a lot of type!

John Gilmore '17 got a chance to print in just about every way available.  Here he is using polyer plates on the Vandercook.

The Studio art course, The Artist's Book and the Film course, Handmade Cinema got together to make a film using letterpress, nature printing and rubber stamps, photo 1

The Studio art course, photo 2

It was a busy time during finals for the Photo 1 and 2 students. 

For History of the Book students as well!

Written by Sarah Smith