For Authors > Author's Guide > Image, Alt Text, and Table Preparation

Image, Alt Text, and Table Preparation

0. Alt text: What is it used for, and how to create it?

Alt text is a short description (often 140 characters or fewer) of a specific visual resource that is not displayed on the page but is embedded in the electronic book and can be accessed via assistive technology. A reader who is visually impaired or uses assistive technology for any reason can have the alt text read to them, thereby allowing them to understand a book’s visual content.

Examples are provided for each type of art discussed below. Alt text is similar to a caption, but intended to be more purely descriptive. Alt text is supplementary to the caption and should not repeat all the same information. Please be sure to provide an alt text with the caption. For other examples and instruction on writing longer descriptions, please see the Describing Visual Resources Toolkit.

1. Overview: What Is Digital Art?

Digital art is any image that has been captured through scanning or digital photography or that has been created using a software program.

University of Michigan Press (UMP)’s most common types of digital art are Scans, Digital Photos, Screenshots, and Vector-Based Graphics. Scans, digital photos, and screenshots render images as a finite number of dots (called “pixels”) per inch, also called “dpi” or “resolution,” which dictates at what size they are able to be displayed on a printed page. Vector-based graphics do not have a finite number of dots, so they are “resolution independent” and can be used at any size without loss of quality.

Scans

These are digitized image files created from a physical piece of art like a print photo, article, or drawing. They are saved in graphic formats such as .tif and .jpg and include two main types:

  • Photo scans or any drawing/chart/graph/map scans that contain gray shading

Alt text example: Black and white photograph, close-up of plant leaf with two drops of water on it.

photo scans that contain gray shading

For more examples of alt text, please see our resource for writing image descriptions or the Describing Visual Resources Toolkit.



  • Black and white line art or text scans that are only solid black and white

Alt text example: Simple line drawing of a flower with five petals. There is one leaf extending from the stem at the bottom of the drawing.

Flower_bitmap image

For more examples of alt text, please see our resource for writing image descriptions or the Describing Visual Resources Toolkit.


Digital Photos

These are images taken with a digital camera, saved in graphic formats, such as .tif and .jpg. See the section on Scans (above) for relevant alt text examples.

Screenshots

Most of the time these graphics are created using the screen-capture keyboard command in web browsers (command+shift+3 on a Mac and PrtScr on a PC). They are then pasted into the relevant document and are saved in graphic formats, such as .jpg and .png. See the section on Scans (above) for relevant alt text examples.

Vector-Based Graphics

These are created from scratch using software (such as Microsoft Excel, Adobe Illustrator, Adobe Photoshop, Sibelius, GIS) and have been saved in the format of .eps. If there are no font issues, .eps files can sometimes be opened and edited again in the original software, especially if the Press owns the same software and is provided both the .eps file and the original application file that the .eps was created out of, such as the .ai file for images created in Adobe Illustrator. Common types of vector-based graphics include:

  • Charts and graphs

Alt text example: Bar graph comparing percentage of gum chewers among voters with the percentage of gum chewers among the general population in 1988 and in 1995. Percentages are shown for the number of men and women in each group and for each group as a whole.

vector chart example page 3

For more examples of alt text, please see our resource for writing image descriptions or the Describing Visual Resources Toolkit.



  • Musical examples

Alt text example: The first three measures of Prelude I in C Major, BWV 846 by Johann Sebastien Bach (1685-1750), scored for piano.

The first three measures of Prelude I in C Major, BWV 846 by Johann Sebastian Bach (1685-1750) scored for piano

For more examples of alt text, please see our resource for writing image descriptions or the Describing Visual Resources Toolkit.



  • Maps

Alt text example: Map identiftying 70 Roman and Latin colonies year 338-100, on the mainland of present-day Italy. The largest clusters of colonies occur in the Central and Southern regions of Italy along its western coast.

Map identifying 70 Roman and Latin colonies year 338-100, on the mainland of present-day Italy. The largest clusters of colonies occur in the Central and Southern regions of Italy along its western coast.

For more examples of alt text, please see our resource for writing image descriptions or the Describing Visual Resources Toolkit.


2. Naming Art Files

Overall guidelines for all projects

Please ensure that each file name is between 5 and 25 characters long.

Do not add spaces; use underscores instead.

Do not add hyphens or any other punctuation (other than the period before the file extension).

Do not include any special characters.

There should only be one period, at the very end before the file extension (.tif, .eps).

Tables are not art and should not be numbered in with the art and should not be listed on the Final Manuscript Submission Log.

Use “Fig” for art other than maps, plates, or music (see below).

Add zeros with the numbers, to help them fall in the right order when viewing all the art. Add one zero if there are 0 to 99 pieces of art, two zeroes if there are 100 or more pieces of art.

E.g.:

  • Fig01.tif (if there are 99 or fewer pieces of art)
  • Fig001.tif (if there are 100 or more pieces of art)
  • Fig04_01_Clark.tif (Meaning, figure 1 in actual text chapter 4 of an edited volume, with the chapter author name being Clark. Even if the edited volume overall has more than 99 pieces of art, as long as each chapter has less than 99 you do not need to add more than one zero.)

Art that is to be used in a gathered art section (also referred to as an “insert” or “plate section”) should have a separate numbering sequence from any art that is placed throughout the text. For art in a gathered section, start the numbering over at “01,” and add the word “Plate” at the start of the name of the art in this section, rather than “Fig.”

E.g.:

  • Plate01.tif

If one book has more than one gathered art section, then please add letters, A, B, etc., after the word “Plate” to designate each section.

E.g.:

The art in the first plate section would be:

  • PlateA_01.tif
  • PlateA_02.tif

And the art in the second plate section would be:

  • PlateB_01.tif
  • PlateB_02.tif

Maps and Musical Examples may be numbered in sequence with other illustrations, following the naming conventions above. Alternately, they may be numbered separately, starting over from “01,” using “Map” or “Music” instead of “Fig” in the file names.

E.g.:

  • Map01.tif
  • Music01.tif

If an illustration has more than one part, please add “a” “b” “c” etc., as needed, right after the figure, plate, map, or music number.

E.g.:

  • Fig04_01a_Clark.tif
  • Fig04_01b_Clark.tif
  • Music01a.tif
  • Music01b.tif

Additional information for monographs

The art can be numbered consecutively, with no need to insert chapter numbers since that can introduce unnecessary confusion.

E.g.:

  • Fig01.tif
  • Fig23.tif

Additional information for edited volumes

Please put BOTH the chapter author name and the number that corresponds to the chapter number, as well as the figure number, into the file name.

When you put in the chapter number and the figure number, again please add the necessary zeroes so the file names sort correctly.

E.g.:

  • Fig03_04_Clark.tif (Clark is the chapter author not the book editor. The “03” indicates that this art is to be placed in text chapter 3.)

3. Scans

Scans are digitized image files created from physical items, such as print photos; slides; original art created on paper or canvas; printed newspapers and magazines; and charts, graphs, and maps that don’t exist electronically. These will be professionally scanned or digitally photographed by the art holder, such as a museum, archive, or library. However, if you need to scan physical art, please use the guidelines that follow.

Scan Types

(a) Photo or Gray-Shaded Scans: If your original is a photograph or a drawing/chart/graph/map/article that contains gray shading (not just solid black), the original should be scanned as “black and white photo,” which may be called “photo,” “continuous tone,” or “grayscale” in your scanning program. (The software that created the image below calls it “black & white.” It’s hard to see in this screenshot, but it has a photo icon to show it’s scanning as a photo.) Scanning software usually has a decent selection tool, so ideally you will adjust the selection window so it frames only the item on the page that you need to scan, if it’s within the context of a larger image. (Note: if you are scanning something that has been previously printed, see below for additional information.)

photo or gray-shaded scans example

In Addition, for Scans of Previously Printed Materials: If your original is a physical item from a newspaper, magazine, book, or any other previously printed source, how you scan it depends on the kind of content.

If the content you need, such as a newspaper article, is black only, has no shades of gray, and does not have a lot of text showing through it from whatever is printed on the other side of the page, it may scan fine as a “Text or Line Art Scan.” You can follow the directions below for “Text or Line Art Scan.” However, if you notice when you try to scan it as “Text or Line Art” that the scan looks very messy, such as from show-through, you will need to rescan it as a “Gray-Shaded Scan.”

If the content you need, such as a newspaper article, has shades of gray in it, includes a photo, or is scanned poorly as a “Text or Line Art” scan (probably due to show-through), you will need to scan it as a “Gray-Shaded Scan.” However, when you do so, some different settings are needed to achieve higher resolution, such as checking the “Descreen” option as illustrated in the image below.

gray shaded scan

(b) Text or Line Art Scans: If your original is a drawing/chart/graph/map/text/article/score without any gray tones in it and consists only of solid black and white, the original should be scanned as “text” (which may be called “bitonal” or “bitmap” in your scanning program), at a much higher resolution (see below). In these scans, each pixel has only one of two values: 100% black or 100% white. Scanning software usually has a decent selection tool, so ideally you will adjust the selection window so it frames only the item on the page that you need to scan, if it’s within the context of a larger image.

Flower screenshot

What We Need from You

(a) Photo or Gray-Shaded Scans that Are Not Previously Printed:

  • 300 dpi at 5 inches wide or more if it’s horizontal, or at 8 inches high or more if it’s vertical.
  • Saved in .tif (best), .jpg, or .png format.

Previously Printed Photo or Gray-Shaded Scans:

  • 600 dpi at 5 inches wide or more if it’s horizontal, or at 8 inches high or more if it’s vertical.
  • Check the box for “Descreen” if the scanning software gives you that choice; if not, don’t worry about it.
  • Saved in .tif (best), .jpg, or .png format.

(b) Text or Line Art Scans:

  • 1200 to 2400 dpi at 5 inches wide or more if it’s horizontal, or at 8 inches high or more if it’s vertical.
  • Saved in .tif (best), .jpg, or .png format.

Keep in Mind

  • If the original looks bad, the reproduction will be worse, even if you do have it scanned at the ideal resolution.
  • Do not artificially “add” resolution into a scanned image in Photoshop after the scanning has been done.
  • If you scan anything with gray tones in it, from a source that is previously printed, the “descreen” function means that your final image will be slightly blurred. In addition, UMP may need to blur it more than what your scanner was able to do. This blurring is necessary, in order for your previously printed image to print successfully.
  • If the scanned or digitally photographed file you receive from the art holder is in color, UMP will convert it to black and white in-house. Please be aware that colors of the same value, such as a dark red and a dark blue, may no longer be distinguishable when converted to gray, so if the color changes indicate something essential in the image, a different image might need to be chosen.
  • If your project has a large trim size, images will need to be scanned larger than these default sizes. Doubling the requested sizes should be sufficient for most images.
  • If your project has art that you have agreed with your acquiring editor will print in color, the above instructions apply, except you will scan the photo in the “color photo” or “color” mode in your scanning software.

4. Digital Photos

Digital photos are images taken by a digital camera.

What We Need from You

  • 300 dpi at 5 inches wide or more. (Ideally, you will provide us with the highest resolution option the camera offers.)
  • Saved in .tif, .jpg, or .png format. (.jpg is probably the camera’s default; it is fine to leave the images as .jpg.)

Keep in Mind

  • Photos should be of good contrast, clarity, and focus. If the original looks bad, the reproduction will be worse.
  • Don’t worry about whatever color mode your image is in; UMP will convert it in-house.
  • If your project has a large trim size, UMP will need to check the art to make sure the files are large enough.

5. Screenshots

Screenshots are created using the screen-capture function in web browsers; they are rarely of sufficient quality for print.

If there is no other option, and a screenshot must be used:

What We Need from You

  • Use the largest monitor you can, with the item/web page as large on that monitor as you can, when you take your screenshot, and provide the screenshot to UMP in that original format.

Keep in Mind

  • UMP may still determine that your screenshot is not usable. (UMP will shrink it down and determine if it hits a bare minimum resolution for printability, or not.)
  • Video stills can also be created in Photoshop, and may be of high-enough resolution, ideally 300 dpi at 5 inches wide. (Video stills created via screenshots will rarely be of high-enough resolution.)

6. Charts and Graphs

Charts and graphs ideally are created from scratch in vector-based software applications, such as Microsoft Excel or Adobe Illustrator.

If the chart or graph exists only as a hardcopy, please see section 2 about scanning. (However, UMP may require you to redraw the art if it does not meet quality requirements.)

What We Need from You

  • Please send us a sample of the art you are creating ahead of time, so we can check it and get back to you with any issues. This is a very important step. There are so many variables at play that we can’t predict or describe all the potential issues ahead of time, and this can save you a lot of time later if we discover that some aspect of what you have done in your sample is not acceptable.
  • We accept charts and graphs created in vector-based software, such as .eps files, .pdf files, Microsoft Word files, and Adobe Illustrator files (.ai). Our ability to use these files depends on the fonts you use, as well as other aspects—please read on!

Keep in Mind

Guidelines for all charts/graphs:

  • Type size: If you are working on a chart that is very large, make sure you reduce it down to the size it will be in your book, about 4.5 inches wide, so you can see if your fonts are large enough. If you are working on a chart that is close to the final print size, 8pt to 10pt is a good font size. Don't use different sizes of type - keep the type size consistent and at a size that will be readable at 4.5 inches wide.
  • Do not use colors other than gray/black. In a printed book, colors will become shades of gray that may look quite similar.
  • Tints: use tints sparingly. If you must use more than one shade of gray, use 20%, 50%, and 80%. Consider using other “fills” such as dots or diagonal lines to help distinguish them. Also, make sure your legend has a large enough fill sample that readers can distinguish them.
  • Black type should not be put on top of any tints darker than 20%.
  • White type should not be put on top of any tints lighter than 40% and should be bold to make sure it is legible. (However, it is better to avoid using white type whenever possible.)
  • All graph/chart rules and axes should be 100% black, rather than gray, so they print sharply. The line width should be between .75pt and 2pt. If you are not able to use 100% black, then the line width should be more like 1 to 2pt. If the line is 100% black, then a line width of 0.75 pt should be fine.
  • Fonts: This is very important: please use Helvetica or Arial if they are choices open to you, or Times New Roman if you prefer a serif font. Do not use Calibri or Cambria. Do not use all caps. Type should not run over lines or over other text. Use only one font if possible; two at the most.
  • If you have the option, it’s best to save your chart/graph as an .eps file or a .pdf file, but see below for additional information about Excel and Illustrator.

In addition, if your chart or graph is from Microsoft Excel:

  • Select your font/graph, and change the font for all type elements so it is Helvetica or Arial (not Calibri or Cambria, which are often the default fonts in Excel). The font size should be between 8pt and 10pt, if possible.
  • In the Chart/Chart Layout/Format section, make sure your axes and lines are set to at least 3/4pt or 1pt.
  • In the Chart/Chart Layout/Format section, with your axes and lines selected, select the “Line” pulldown and then choose “Line Effects,” then click on “Solid”, and ideally the color is the second choice under “Theme Colors,” which is black (not gray). The graph lines will print more sharply if they are black rather than gray.
  • When you are ready to move your chart out of Excel, save it as a .pdf file.

If your chart or graph is an .eps or a .pdf and you have access to Adobe Illustrator:

  1. Open your .eps file or .pdf file in Illustrator (if it was created in something else or before you save your final file out of Illustrator), and look it over to make sure everything looks like it should - all fonts and all elements are present and correct.
  2. Then go up to “Select” in the top menu, and choose “All” so everything in your document is selected.
  3. Then go up to the “Type” menu and choose “Create Outlines.” Then proceed and save the file as an .eps file. This ensures that UMP will have no issues with any fonts in your files.

Font issues are the most common reason why .eps and .pdf files are not usable by UMP, so please take the time to do these steps, if you have access to Adobe Illustrator.

7. Musical Examples

Musical examples ideally are created from scratch in vector-based software applications, such as Sibelius or Finale.

If the musical examples exist only as hard copy, please see section 2 about scanning. (However, UMP may require you to redraw the musical examples if they do not meet quality requirements.)

What We Need from You

  • Please send us a sample of the files you are creating, ahead of time, so we can check it and get back to you with any issues.
  • We accept musical examples created in vector-based software as .eps (best) or .pdf (second best) files. We accept .tif files if UMP has font problems with the .eps or .pdf files. For both .eps and .pdf file types, it is important that you check to see what font-embedding or font-outlining options you have in your software and embed the fonts when you are creating the file type.
  • If for some reason these formats are unsuccessful (including if UMP is not able to use your files due to the fonts dropping out) and you need to export as .tif files, the .tif files need to be at least 1200 dpi.

Keep in Mind

Guidelines for musical examples:

  • It is best if all elements are in 100% black, no shades of gray, if this is possible.
  • Keep in mind the book’s trim size; the music will most likely be printed around 4.5 inches wide, so do not make your originals so wide that all elements within it will become too small to read on the printed page.

If your musical example is an .eps or a .pdf, and you have access to Adobe Illustrator:

  1. Open your .eps file or .pdf file in Illustrator (if it was created in something else or before you save your final file out of Illustrator), and look it over to make sure everything looks like it should - all fonts and all elements are present and correct.
  2. Then go up to “Select” in the top menu and choose “All” so everything in your document is selected.
  3. Then go up to the “Type” menu and choose “Create Outlines.” Then proceed and save the file as an .eps file. This ensures that UMP will have no issues with any fonts in your files.

Font issues are the most common reason why .eps and .pdf files are not usable by UMP, so please take the time to do these steps, if you have access to Adobe Illustrator.

8. Maps

Maps ideally are created from scratch in vector-based software applications, such as Adobe Illustrator, Adobe Photoshop, and GIS-based applications.

If the map exists only as a hard copy, please see section 2 about scanning. (However, UMP may require you to redraw the art if it does not meet quality requirements.)

Note: A screenshot or “print to PDF” of an online map, such as Google maps, is almost never of high-enough quality for printing. However, if the map is a static graphic file that had been uploaded to a website, for downloading, it might be of high-enough quality, if a large enough version was uploaded. Check to see if there are download options for the map on the page where you found it.

What We Need from You

  • Please send us a sample of the art you are creating ahead of time, so we can check it and get back to you with any issues.
  • We accept maps created in vector-based software as .eps (best) or .pdf (second best) files. We accept .tif files if there are font problems with the .eps or .pdf files. For both .eps and .pdf file types, it is important that you check to see what font-embedding or font-outlining options you have in your software and embed the fonts when you are creating the file type.
  • If for some reason these formats are unsuccessful (including if UMP is not able to use your files due to the fonts dropping out) and you need to export as .tif files, the .tif files need to be at least 1200 dpi.

However, please read on!

Keep in Mind

Guidelines for map creation:

  • Keep in mind the book’s trim size; the map will most likely be printed around 4.5 inches wide, so do not make your originals so wide that all elements within it will become too small to read on the printed page.
  • Tints: if you need to use more than one shade of gray, they need to be sufficiently different from each other to be distinguishable. Use 20%, 50%, and 80%.
  • Do not use colors other than gray/black. In a printed book, colors will become shades of gray that may look quite similar. (However if your book is going to print in color this does not apply.)
  • One consistent line weight, of 1/2pt to 1pt, is preferred; use no more than two different line weights.
  • Black type should not be put on top of any tints darker than 20%.
  • White type should not be put on top of any tints lighter than 40% and should be bold to make sure it is legible. (However, it is better to avoid using white type whenever possible.)
  • Fonts: This is very important: please use Helvetica or Arial if they are choices open to you, or Times New Roman if you prefer a serif font. Do not use Calibri or Cambria. Use all-caps sparingly, and only if necessary. Type should not run over lines or over other text. Use only one font if possible; two at the most.
  • Type size: If you are working on a layout that is very large, make sure you reduce it down close to the size it will be in your book (about 4.5 inches wide) so you can see if your fonts are large enough. If you are working on a layout that is close to actual size, 8pt to 10pt is a good font size. Do not use type smaller than 7pt. When the map is displayed at its actual size; readers will not be able to read it.
  • Type placement: Type should not run over other text. Whenever possible, type should not run over lines. Leave enough spacing between labels.
  • If you have the option, it is best to save your chart/graph as an .eps file or a .pdf file.

If your map is an .eps or a .pdf and you have access to Adobe Illustrator:

  1. Open your .eps file or .pdf file in Illustrator (if it was created in something else or before you save your final file out of Illustrator), and look it over to make sure everything looks like it should - all fonts and all elements are present and correct.
  2. Then go up to “Select” in the top menu and choose “all” so everything in your document is selected.
  3. Then go up to the “Type” menu and choose “Create Outlines.” Then proceed and save the file as an .eps file. This ensures that UMP will have no issues with any fonts in your files.

Font issues are the most common reason why .eps and .pdf files are not usable by UMP, so please take the time to do these steps, if you have access to Adobe Illustrator.

9. Tables

Tables can present some challenges for the typeset page, and some additional unique challenges for the electronic versions of your work. Some ebooks are read on small mobile devices that have screens that are too small for wide tables. In addition, UMP prioritizes setting tables as “live” text rather than as graphics in our reflowable-text ebooks, to make the content more searchable, usable, and accessible.

For maximum usability by readers of your work, regardless of whether the format is print or electronic, here are some elements to consider when creating your tables:

If the material you are discussing could be integrated into the text, perhaps by reworking some of it into regular text, and/or some as a numbered list or a two-columned list, instead of pulling the information out separately into a table, please choose to integrate the information into the text.

This is especially true if the information you are considering putting into table form is very wordy. The longer the text phrases are, the higher the likelihood of that material being more difficult to read in an electronic version.

If the material you are discussing needs to be in table form, it is better to have a higher quantity of simpler tables, than a smaller quantity of more complex tables.

A key element of a “simple” table is one that does not have too many columns across and one in which column content is brief. If it is possible, it is better to split your material into multiple tables, say with 2 to 4 columns across each, than to create one large table with 5 to 8 columns across. In addition, the less-wordy your columns, the better, since the table columns will be compressed when displayed on small mobile devices. This affects the print book, too, of course; if your table columns are very wordy, you can fit fewer of them across your standard 4.5 inch book page width. If your table columns only contain numbers, then you can fit more of them across your standard 4.5 inch book page width.

Examples

This table has only 2 columns, and neither column is long or wordy. Therefore the table will do very well in an epub, even when read on older versions of small mobile devices.

2 column table example

This table has 5 columns, which is an amount that can sometimes be okay, if the columns are not very wordy. Therefore, this table will be okay for an epub that is read on most devices, including newer mobile devices. However, there is a risk that on older mobile devices, including older Kindles, that the last 1 or 2 columns might be cut off.

5 column table example

This table has 7 columns, though the columns are not very wordy. Therefore, this table will be okay only for an epub that is read on larger devices, like an iPad; the table is wide enough that when small mobile devices compress the content to fit, the columns may get too compressed to read. And on older Kindles, or other older mobile devices, the last few columns will be cut off.

7 column table example

This table has only 3 columns, but the columns are very wordy. Therefore, this table will be okay for an epub that is read on larger devices, like an iPad. On small devices, however, the columns will be squeezed, and the type may break into very narrow columns that are too close together and difficult to read. (See the example below, which shows how the wordy text from Column 1 might look when read on a small electronic device.) If it’s possible to work this content into the text rather than displaying it in a table, that would be better for your epub readers.

3 column table example pulled type example

Do not use gray shading or graphic elements in your tables, since they will disappear in the epub.

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