Frequently asked questions

This page covers a number of questions that may arise before or while you're using Dontprint. If your question is not answered on this page (and only then!) you can get personal support.

About Dontprint

What is Dontprint?
Dontprint is a free browser extension for Google Chrome and Mozilla Firefox. It is a small piece of software that you can easily install to augment the functionality of your web browser.

Dontprint makes it easy to send PDF documents, such as scientific articles, in an optimized layout to your e-reader device. With Dontprint, sending scientific articles to your e-reader is even easier than printing them on a traditional printer. When you come accross the web page of a scientific article from any mayor publisher a Dontprint icon (Donptint icon) will appear in the address bar. With a single click on that icon Dontprint downloads the PDF file of the article, reformats it so that you can read it comfortably on the e-book reader's smaller screen, and sends it to your device.

For a full demonstration of Dontprint's features, go to the feature tour.

Who would want to use Dontprint?
Dontprint may be useful to you if you own an e-reader device and if you sometimes read PDF documents on the web.

If you are a scientist and read a lot of articles from scientific journals then Dontprint is exactly right for you. Dontprint knows how to interpret the websites of many popular scientific journals and preprint servers. When you browse to a web page that represents a scientific article a small Dontprint icon (Dontprint icon) will appear in the address bar. When you click this icon Dontprint will download the PDF document of the article, optimize the layout so that you can read the article comfortably on a small screen and then send the article to your e-reader. The layout optimizer even knows how to handle multi-column articles with figures and complicated equations.

Dontprint may also be useful to you if you are not a scientist but you sometimes come accross PDF documents which you would like to read on your e-reader. You can use Dontprint with any PDF document that's either on your computer or that you come accross on the web. The optimization of the layout for a small e-reader screen works best for PDF documents that contain mainly text.

I can already send PDF Documents to my e-reader by e-mail. What does Dontprint bring to the table?
Most scientific articles are layouted in a form that is appealing to read in a printed journal. Unforunately, these documents are usually almost unreadable on a small e-reader screen. Dontprint solves this problem for you. When you send an article to your e-reader, Dontprint rearranges the text flow so that you can read the article comfortably on your e-reader. This works great even with articles that have several columns and contain complicated equations or figures.

In addition to the layout optimizations, using Dontprint is much simpler than sending articles manually by e-mail to your e-reader. Without Dontprint, you would have to download an article, switch to your e-mail application, compose a new message, add an attachment, locate the downloaded article in your file-system and finally send the message. If you install Dontprint, it will add a small icon (Dontprint icon) to your web-browser's address bar whenever you're reading the abstract of some article from a scientific journal or a preprint server. Just click that icon and the article will automatically be downloaded, converted, and sent to your e-reader. That's even easier than printing on a traditional printer! Of course, you can also use Dontprint to send PDF documents that are already stored on your computer.

In case you're interested in the details: Dontprint internally uses a third-party tool called "k2pdfopt" to optimize the layout of articles and some of the functionality developed for Zotero to detect and parse journal websites.

Will Dontprint work with my e-reader?
Dontprint generates documents in the PDF format. So if your e-reader can display PDF documents then you can use Dontprint. This should cover almost all e-reader models. If your e-reader is an Amazon Kindle then you can even configure Dontprint to send the optimized documents automatically to your Kindle's e-mail address. Alternatively, you can also choose to transfer documents manually via USB. This works with almost all e-readers. The developer of Dontprint is not affiliated with any e-reader manufacturer or retailer.
How much does using Dontprint cost?
Dontprint is completely free of charge. I originally wrote this add-on for my personal use when I realized that others might find it useful, too. Currently, Dontprint does not display any advertising, although this might change with future versions.
How is Dontprint licensed?
Dontprint is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License, version 3 (AGPLv3), as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

A copy of the GNU Affero General Public License version 3 is available on the page "license agreement".

A small part of Donptrint is implemented as a script that runs on a web server. The above copyright statements also apply to the server-side part of Dontprint.

The source code of Dontprint (including the small server-side part) is available on GitHub. The source code of the third-party utility "k2pdfopt", which is used to optimize the layout of PDF documents, is available on the original website.

Who developed Dontprint?
Dontprint was developed and is maintained by Robert Bamler. Please note that Dontprint heavily relies on parts developed by third parties:
  • To optimize the layout of PDF documents for small screens Dontprint uses a program called "k2pdfopt", developed by William Menninger.
  • To detect web sites of publishers and extract meta data such as article titles and journal names Dontprint uses parts of the functionality developed for Zotero. Zotero is the trademark of George Mason University. The developer of Dontprint is not affiliated with Zotero.

Installation and preferences

Where can I get Dontprint?
Click the "Download"-link on the very top of this page.
What is my e-readers e-mail address?
You can configure Dontprint to send documents to your e-reader by e-mail.

If your e-reader is an Amazon Kindle then its e-mail address typically consists of a name that you chose when you bought the device followed by one of the suffixes "@free.kindle.com", "@kindle.com", or "@kindle.cn". If you can't remember which e-mail address you picked there are two ways to find it out:

  1. On the device itself, go to the home screen, press the menu key and select "Settings" or "Preferences". Step through the settings like you would browse through the pages of a book until you find your Kindle's e-mail address.
  2. Log in to Amazon's "Manage Your Content and Devices" page, click on "Your Devices", and select your preferred device if you have more than one. Your device's e-mail address will be displayed (see screenshot below). Screenshot: Where to find your Kindle's e-mail address on the Amazon web site

If your e-reader is is not an Amazon Kindle but supports receiving documents by e-mail then you probably had to pick an e-mail address when you bought the device or when you used it for the first time. If you don't remember the e-mail address that is tied to your e-reader, look for it in the settings on the device itself or on the website of the company that sold the e-reader to you.

If your e-reader does not support receiving documents by e-mail then you can still use Dontprint. On the welcome page, simply choose the option to transfer documents to your e-reader manually.

What is an "approved personal document e-mail"?
If you want to use the e-mail sending feature of Dontprint, then you may have to tell your e-reader's vendor to allow receiving e-mails from "noreply@dontprint.net".

If your e-reader is an Amazon Kindle then you have to tell Amazon that Dontprint is allowed to send documents to the device. To do so, follow these steps: Screenshot: list of approved personal document e-mails on the Amazon web site

  1. Log in to Amazon's "Manage Your Content and Devices" page.
  2. Click on the "Settings" tab and find the section "Approved Personal Document E-mail List" (see screenshot on the right).
  3. Add the address "noreply@dontprint.net" to the list. Dontprint sends e-mails from this address.
What is the screen width, height and pixels per inch of my e-reader?
Dontprint rearranges the layout of articles so that you can read them comfortably on your e-reader. You get the best results if you tell Dontprint the exact size of your e-reader's screen. Note that this is an "effective" screen size which is usually a bit smaller than the screen size that is specified by the manufacturer because most e-readers add some white margins around displayed PDF documents.

To find out your screen size choose go to Dontprint's settings page, pick the "Device" tab and make sure the correct e-reader model is selected (or select "other" if your e-reader model is not in the list). Then click the button labeled "Help me find out the correct document size".

The "pixels per inch"-value only influences the font size of the documents that will be sent to your e-reader. Usually, it is best to set this to the recommended value. If you find the font size too small, increase the "pixels per inch"-value. If you find the font size too large, set "pixels per inch" to a smaller value.

Privacy

How can I be sure Dontprint does not secretly violate my privacy or abuse my e-reader's e-mail address?
The complete program code on which Dontprint runs is publicly available. This includes even the small part of Dontprint that runs on a webserver. Since everybody on the web can read and inspect the code that runs Dontprint it cannot include any hidden privacy violations.
Will Dontprint ever send any e-mails to my e-reader without my explicit request?
No. Dontprint only sends an e-mail to your e-reader if you activate the e-mail sending feature. Even then, Dontprint will only send one e-mail to your e-reader each time you instruct it to send a specific document and it will not send any additional files other than the document you asked for. For proof of this claim, see "How can I be sure Dontprint does not secretly violate my privacy or abuse my e-reader's e-mail address?".
Does Dontprint save my e-reader's e-mail address on a webserver?
No. If your e-reader is able to receive Documents via e-mail attachment, then you can configure Dontprint to send converted documents directly to your device. In order to prevent abuse of our e-mail sending infrastructure by spammers, we require you to verify your e-reader's e-mail address before you can use it. The verification is a simple process where we send you a small document with a random code, which you have to type back to Dontprint in order to proof that the specified address really belongs to you.

Whenever you instruct Dontprint to send an article to your e-reader via e-mail, we check if the e-mail address in question has already been verified. To do this, we compare a checksum that is computed from your e-mail address against a list of checksums of verified e-mail addresses. If the test is positive, we send the e-mail and then immediately forget your e-reader's e-mail address. Only its checksum remains in our database, but it is calculated in such a way that it is impossible to reconstruct the e-mail address from the checksum.

The extra step with the checksum was chosen to even further increase the level of security for your personal data. This way, we can ensure your privacy even in the unlikely event that an intruder would gain access to our database.

How does Dontprint use my Facebook account data if I choose to share an activity on Facebook?

Short answer: Not at all.

Longer answer: After dontprinting an article, Dontprint provides to you the option to share this activity on Facebook. Sharing on Facebook is a completely voluntary action, which has no influence on the further behaviour of Dontprint. If you do decide to share an activity on Facebook, you will be asked to sign in to your Facebook account and to grant Dontprint the necessary permissions to write to your Facebook timeline. You will see a warning message saying that Facebook is going to give Dontprint read-access to your public profile. This means that Dontprint could, in theory, find out some basic information about you, such as your name, profile picture, approximate age, gender, language, and country. These are some basic data that are also visible to anyone in the world on your public Facebook profile. Therefore, Facebook is willing to give these data also to every app that uses some of their features. However, Dontprint does not even read out any of these data because they are not necessary to write the post to your timeline. In particular, Dontprint does not use your Facebook ID to track your activity. For proof of this claim, see "How can I be sure Dontprint does not secretly violate my privacy or abuse my e-reader's e-mail address?".

When does Dontprint post to my Facebook timeline?
Dontprint will never post to your Facebook timeline without your explicit request. After successfully dontprinting an article, Dontprint displays a button labeled "Share on Facebook". If you click this button, you instruct Dontprint to post a short notice to your Facebook timeline that reads something like "John Doe dontprinted an article by Jane Doe". You can choose the audience for which these kind of posts will be visible. Dontprint posts only once each time you click the "Share on Facebook" button. The next time you want to share an activity on Facebook, you will have to click that button again.
Which kind of data does Dontprint send from my computer?
Dontprint never sends any usernames or passwords from your computer. If you choose to activate the e-mail sending feature of Dontprint, then Dontprint will send converted documents to your e-reader by e-mail attachment. Dontprint uses the e-mail address that you provide solely for the purpose of sending your requested documents. We will never send you any advertisements, nor will we ever hand over your e-mail address to third parties. In fact, we don't even store your e-mail address on our server.

The following list explains all situations in which Dontprint sends any data from your computer.

  • Retrieving articles from journal websites: When you click on the Dontprint icon on the website of a journal Dontprint downloads the article's PDF file and some associated meta-data, such as the title of the article and the name of the journal. To do so, Dontprint has to send some requests to the web-site of the journal. These are similar to the requests that your web browser would usually send out if you downloaded the article manually.
  • Sending documents by e-mail attachment: If you choose to activate the e-mail sending feature then Dontprint sends an e-mail to your e-readers e-mail address every time you instruct it to do so. The e-mail contains a single attachment (the document you requested) along with some meta data about the article (such as its title). The e-mail will not be sent to any recipients other than the one you specify and it will not be stored by Dontprint once it is sent.
  • Voluntary posts to your Facebook timeline: After successfully dontprinting an article, Dontprint displays a button labeled "Share on Facebook". If you click this button, you instruct Dontprint to post a short notice to your Facebook timeline that reads something like "John Doe dontprinted an article by Jane Doe". You can choose the audience for which these posts will be visible. Dontprint will never post to your Facebook timeline without your explicit request.
  • Voluntary anonymous reports of journal margins: When you dontprint an article from a journal you may sometimes have to set the page margins manually because Dontprint does not yet know the correct margins for this specific journal. Since this can be annoying, Dontprint provides to you the option to report the selected margins to its developer so that these settings can be built into future versions of Dontprint. This data does not contain any user-specific information (such as e-mail addresses or user names). You can inspect the data before it is being sent and reject the transmission for each case individually. You can also turn off this feature altogether on the "Advanced" tab of Dontprint's settings dialog.
  • Voluntary anonymous reports of device settings: When you set the screen size of your device you can voluntarily choose to report those settings to the developer of Dontprint so that the default values for the screen settings can be updated in future versions of Dontprint. The data will only be sent if you actively opt-in to do so and you can inspect the data before its transmission.
  • Software updates: To update Dontprint and to download and update the third-party utility that rearranges the layout of the PDF files, your browser needs to send normal HTTP requests to the web server. The same requests would be sent from your computer if you downloaded the corresponding files manually.
Future versions of Dontprint may contain features that bring along other scenarious where data is sent from your computer. However, even future versions of Dontprint will never send any passwords from your computer without your explicit permission and will never send any e-mail addresses for reasons other than sending out e-mails you explicitly requested.
I'm no longer using the e-mail sending feature of Dontprint. Can I revoke the permission to send e-mails to my e-reader that I granted to Dontprint?
Yes. This is usually not necessary, but to give you full control, you can revoke the permission here. If you ever want to use the e-mail sendnig feature again, that's no problem. The next time you instruct Dontprint to send an article you will be asked to re-verify your e-reader's e-mail address.