Guidelines for

Illustration & Art

Image Guidelines 

Images, whether photographs, illustrations, graphs, or maps, appeal to readers on an aesthetic and intellectual level. Your type of book and contract determine whether images are used and impose limits for the quantity and type we are able to produce in your book. Does your book contain images? By this point, you will have run images by your editor who may have had feedback on how essential a particular image is to furthering the intellectual point of your book. Permission fees are your responsibility and can add up quickly in an image-heavy work (see our permissions guidelines for more information). 

How many and what kind of images? 
Your contract will specify the number and type of images in your book, on which you and your editor have agreed; please review the image specifications in your contract prior to preparing your image package. 
If you decide after signing your contract that it is necessary to alter your image package, please consult with your editor immediately as this can affect the complexity, schedule, and cost of your project. 

What images work best for book printing? 
Supply high-quality files that appear crisp and clean and are large enough for your book trim. Book printing requirements are different from other types of publications and printing (blogs, journals, etc.), so the following guidelines explain the technical aspects of procuring high-quality files suitable for a book press. 

File Types 

  • Acceptable image file formats:  TIFF or JPEG*, EPS or AI** 
  • Unacceptable image file formats:  Word, Excel, PNG, GIF, PDF, PowerPoint, Freehand, CorelDraw, Visio Consult your editor immediately if these are the only file types available to you. 

These formats are not acceptable as they are not encoded for professional printing presses. They are highly compressed and inherently lower in resolution for intended use in digital environments (websites, presentations, file sharing, emailing, and office digital printing). 

*Important note regarding JPEG & TIFF 
The JPEG format is often used for file transfer because of its compression capability; when compressed to smaller file size, the quality of the image is mostly retained while making it easier to transfer. 

Unfortunately, compression is accomplished by discarding some of the data that makes up the image. Each time a JPEG is opened and resaved in the JPEG file format, image degradation results. The TIFF format does not risk this sort of degradation, as it retains/freezes original quality and file size; these are usually larger in size (MB). 
If you acquire an image from a library, museum, or stock photo agency, request the TIFF or EPS format. If JPEG is the only file format available, do not open, edit, or resave the image before submitting it. 

Read more about raster, or pixel-based, graphics

**EPS and AI files EPS and AI formats are used for vector graphics – meaning, pixels are not used to create the image; instead, images are generated using points connected by lines. The advantage of vector in printing means there is no concern about resolution. Art can be sized as small as a postcard or as large as a poster without any effect on its crispness and quality. If you or a designer have created files in AI, the best file format to submit is the original working AI or EPS file, rather than exporting as TIFF or JPEG. 

Read more about vector graphics
Read more about raster vs vector results
Read more about image file formats

Gathering and Submitting Files 
It is your responsibility to prepare your image package for submission according to press guidelines. If assistance is required for compiling your package, contact your editor for further direction. 

Gather the highest-quality version of your images for submission. Original sources are often best, or those provided directly from a designer. Do not supply pasted or resaved files. Exported files are acceptable if exported directly with required resolution or acceptable formatting. If files do not meet press-specs, there is potential for an image to be cut. 

If you are generating your own line art, please be in contact with your editorial assistant to request either a document of specific instructions to ensure your files are print-ready or for a list of freelancers who can create these images according to JHUP guidelines for you. 

A form is required each time you submit images to your Editorial Associate. This assists in tracking files and ensures that the correct file has been transferred for pre-production. 

One image, one file 

  • Submit every image as a separate file. Image files can be transferred using Dropbox or another file-sharing system as the files will be too large to attach via email. Supply an updated form each time, so it is clear what should be included in the file transfer. 

Multi-part images / figures 

  • For instances where you would like two or more images presented together in the book (sometimes called composite images), do not combine images into a single file; rather, submit each file individually and send an explanation or mock-up of how these images should be placed together. (In addition to the labeling system described below, you might label these files as A, B, C, D, etc., to indicate relative order.) Each image in a multi-part figure is counted toward the total image count for your book (if your figure is comprised of A, B, C, this equates to three images in a total image count).

Labeling image files

  • For each file submitted, clearly label to indicate placement cited in the manuscript text (e.g., Figure_01-01.jpg, or, if your images will appear in a gallery, Plate_01.tiff). The numbering used in the filename should correspond to the numbering system within the manuscript, indicating approximate placement (see style guidelines). Images within galleries should be labeled as “Plates” rather than “Figures” to prevent confusion. 

Color preparation

At times, color adjustment can reduce the quality of an image file. Whether your book is in color or black and white, it is not necessary to adjust or convert your images for submission, as this can be done by the Press in the pre-press stages. Where there are exceptions, the Press will reach out to you. 

For images that will be produced in color for which you have RGB files, do not take it upon yourself to convert the file to CMYK. We will do that here at the Press. It is important that color used to represent data or information has been prepared to be accessible according to color blindness standards. 

If you are unfamiliar with color-blindness palettes, please refer to these on-line resources:

How to Use Color Blind Friendly Palettes to Make Your Charts Accessible 

Designing for Color Blindness 

Black & White
For images you have in color that will be produced in black and white in the book, do not take it upon yourself to convert the file to grayscale. We will do that here at the Press.

Color-data. If a map, chart or graph uses color to represent data, this must be prepared in grayscale prior to submission so that the values translate as intended. See “Graphs, charts, diagrams" below. 

Resizing and cropping
Do not resize your images, as this can pixelate, blur, or distort the quality of the file. If you wish for a cropped portion of an image to be reproduced in your book, supply the high-resolution image and indicate the crop area to your editor as a note or mock-up, who can pass that information along to the design and production department. 

Common Types of Images & Resolution 
Book printing requires high resolution files due to the printing press process. Resolution is measured using ppi – or pixels-per-inch – which is translated to dots on a press (dpi, or dots-per-inch). The more pixels to translate to dots, the clearer an image. Fewer pixels means fewer dots, which yields blobby, blurry or incoherent results. 

Computer-made images require 1200ppi resolution for clear printing on a book press. Resolution for any other type of image is never less than 300ppi. 

Photographs or scans
(300 ppi or greater TIFF or JPG) (maps: 600-1200ppi TIFF or JPG) 
We accept high resolution digital photographs or scans in either original JPEG or TIFF format that are a minimum 300 ppi at their final intended print size. Print-size may vary depending upon the trim size of your book, i.e. for a 6 x 9 book, the image area tends to be around 4.25” x 7”. Images which may be too small in resolution or dimension or too resampled to reproduce well in printing will be flagged with the possibility of being cut. 

  • Illustrations, cartoons, or “pen and ink” style drawings. 
  • Computer-created (vector AI or EPS) or (1200ppi TIFF or JPG) 
  • Scanned/photographed illustrations - (600-1200ppi TIFF or JPG) 

If you commission illustrations for your book, those prepared in Adobe Illustrator and supplied as either AI or EPS files, are best. However, if you are working with an artist who creates line drawings and then scans or photographs them at high resolution, these files should be between 600 and 1200 pixels per inch (ppi). 

Graphs, charts, or diagrams

  • Computer-created (vector AI or EPS) or (1200ppi TIFF or JPG) 
  • Scanned or exported (1200ppi TIFF or JPG) 

If your book presents data in a visual representation, vector files prepared at final intended size in Adobe Illustrator* should be supplied as either AI or EPS files. 

  • Bar graphs should use black, white, and flat shades of gray (e.g., 20%, 45%, or 70% black) to differentiate data areas (do not use patterns to differentiate data as these do not print well). 
  • Text in the graphs should be no less than 8 point in a standard font such as Myriad Pro, Helvetica, or Arial. Legibility should be assessed at the final intended image size. Text smaller than 8 point in final size risks not printing cleanly or legibly. 
  • Line weight for the graphs should be no less than 0.25 point. .5 or 1 point stoke weight prints well. 

*If you are unfamiliar with this software and are not working with a designer to create AI or EPS files, then discuss with your editor if the press will consider redrawing graphs from another format (Word, Excel, or PowerPoint). 

Note on color: if your book will be printed in color and color represents data, be sure to review color blindness guides to ensure legibility and accessibility of your data. 

How to Use Color Blind Friendly Palettes to Make Your Charts Accessible 

Designing for Color Blindness 


  • Computer-created or exported (vector AI or EPS) or (1200ppi TIFF or JPG) 

If you are reproducing historical maps photographed professionally, please follow the guidelines above for Photographs or scans. If your book will contain original maps, it is ideal to hire a freelance cartographer who can, as a work-for-hire, prepare the maps in Adobe Illustrator to produce vector EPS files. These are files that remain crisp as they are not generated using pixels, and can be created at the size required in your book. Text and legends in the maps should be no less than 8 point in a standard font such as Myriad Pro, Helvetica, or Arial so as not to risk the text not printing legibly. The line weight for the maps should be no less than 0.25 point. Should you use specialized software for tracking data, for example, migratory patterns of particular species or atmospheric patterns, talk with your editor and the Press production coordinator about file output to ensure the files you are producing are suitable for print. 

Note on color: if your book will be printed in color and color represents data, be sure to review color blindness guides to ensure legibility and accessibility of the data How to Use Color Blind Friendly Palettes to Make Your Charts Accessible.

Download Illustration & Art Guidelines