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Comment by GnarfGnarf | Hacker News Reader

Although I agree that PDFs (and screens in general) are not the best for reading, the PDF file format is a minor miracle. It is a thing of beauty, combining text and graphics to preserve the author's design.

I have built a business on PDF. I develop graphics software, enabling my customers to create large charts (36" x 96" and bigger) in PDF format, which they can take to the print shop for printing on large-format plotters and printers.

The sharp crispness of PDF text and vector graphics allows unlimited zooming while never pixellating (except the photos, of course).

If you are familiar with the technical specifications of PDF (1,300 pages 2006 ed.), you will appreciate the sophistication and power of the internal structure of PDF.

As an exchange medium, PDF has made huge contributions to commerce, technology and culture.

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Okay, but that’s not disagreeing with the article’s point, which is that it’s a bad UI for communicating digital content to non technical end users. The author supports its use for its primary case, and how you use it, which is printing.

That may be the author's point, but what he says is that PDF is unfit for human consumption. Which is absurd. As a scientist, PDF journal articles are almost always easier to read than the HTML version -- the graphics are of much higher quality, two column printing is more common, scientific equations and fonts are rendered better, etc. etc.

If the article title were "PDF -- unfit for web presentation" the author might have a stronger case.

> That may be the author's point, but what he says is that PDF is unfit for human consumption. Which is absurd.

You're quoting the click-baity title, but failing to actually read past the article summary's first sentence.

The summary's very first sentence states "Research spanning 20 years proves PDFs are problematic for online reading." This sentence alone frames the problem, and explains the whole point of it.

Sounds like we can all agree that this page should have a better, more accurate title.

No, it sounds like people shouldn't criticize a text when they clearly haven't read it.

> That may be the author's point, but what he says is that PDF is unfit for human consumption. Which is absurd. As a scientist, PDF journal articles are almost always easier to read than the HTML version

I don’t think the author was disagreeing with that either! They were saying, rather, that this effect is due to a collective failure to use HTML properly. If all you want to do is reproduce the physical pages of an article onto a digital device, and gain no more functionality (like text search, hyperlinking, reformatting), the author agrees PDF is great for that. But if you want to exploit all the features digital devices and the web offer, PDF constantly gets in your way.

I still tend to agree with fastaguy88, PDF's are still my preferred format for reading science data, even on my digital devices. HTML data just doesn't have the font quality, layout rendering, and ability to ensure all the appropriate data is saved without requiring some remote server (and login!). My preferred digital device is a 12" iPad Pro as it shows the pdf in native 8 1/2 by 11 size. That makes me happy! Change the device form to match PDF.

Yes, completely agree. Scientific articles on a phone are terrible--open the PDF and zoom/scroll around? You know exactly what to do and how it works.

> But if you want to exploit all the features digital devices and the web offer, PDF constantly gets in your way.

I agree, PDFs are indeed poor and ill-suited for online reading. They are not reflowable, and PDF authors force a pagination format that more often than not are only readable in a device by chance or if readers use a large format device such as a large tablet. Hell, some PDFs are even unreadable and impractical to read in 13' laptop screens with 1980*1200 resolution.

You should give HTML journal reading another chance. The journals that let you see citations without losing your place in the article are great.

> As a scientist, PDF journal articles are almost always easier to read than the HTML version -- the graphics are of much higher quality

You mean they look better on paper than on screen? And what magic improves quality of graphics?

The auto-reflow of HTML often puts things to weird places. I'm sure it can be done properly as well, but auto-converting a PDF or LaTeX document to HTML results in crappy layout. I always download the PDF when given the option, because the the actual authors spent a lot of time to make sure everything is at the right position and everything looks as intended. Sure if the culture changed and scientists now learned web dev instead of LaTeX and put in the same effort into producing production quality, polished HTML instead of PDF, it may work as well. But scientists need to send LaTeX and PDF to journals and conferences, so you can't expect them to put in double effort. Also, making sure that things look good in all browsers is just a way bigger job than making sure a single PDF looks as it should.

I find that modern web UI are increasing shity on the desktop. In particular increasingly dog slow. But well designed pdf documents are still very good. And you can save a pdf locally.

Seriously html is used mostly for delivering spam and porn. And pdf's excel for technical documents.

> Seriously html is used mostly for delivering spam and porn.

Oh come now. I know we all like to hate on the modern web but this just isn't true. Wikipedia, CNN, Amazon, etc all use HTML.

> But well designed pdf documents are still very good.

You're just spewing a tautology. I mean, a well designed thing is still very good? Come on.

> And you can save a pdf locally.

You can also save epub and even HTML docs locally. That doesn't add much to the discussion.

> Seriously html is used mostly for delivering spam and porn.

It sounds like you're trying to force a morality-based argument to compensate for your lack of meaningful, rational points to make in favour of PDFs.

> And pdf's excel for technical documents.

They really don't. PDFs show good results in documents intended to be printed on paper following a very specific format, or whose main purpose is to deliver high-resolution vector graphics content intended to be printed.

Once your usecase consists of consumption with a electronic device, which involves delivering reflowable content that reflects personalized settings such as reader-specific accessibility settings and device properties, PDF fails to be an adequate option.

I’m going to bite. The web site we’re discussing is full of poor points too. The person you are responding to makes some good points.

- once you’ve saved it as a pdf you can email to anyone. Most (all?) phones support it out of the box. They can then print it out and you can be sure that the entire page is rendered correctly. If you try and save that as an ePub, lots of people won’t know how to open it. For HTML files; often the default HTML store is a browser specific format. Even more often there’s some dependency that means that the page doesn’t actually render after the web site changes (e.g. it missed a dependency or because of JavaScript use or because the format changed between versions). This is one of the reasons why tickets for events come via pdf.

- read only. Want to send your CV and make it difficult for the recruiter to edit. Perfect solution is to use pdf. You also know that the pdf will look the same to the people reading it (and printing it) as when you created it.

- want to create a pdf really easily? Print to pdf. Done. Want to reliably do that to HTML. Good luck. Often there are weird issues that pop up. It often doesn’t render properly once the complexity of the document becomes slightly involved.

- PDF’s excel for technical documents. Yeah, I agree with this. They’re great at providing professionally rendered files, guaranteeing a rendered look across technical fields. This is why they’re used in research. Your argument boils down to ‘the pdf requires a very specific format’. Yes. That’s the intent behind pdf. It doesn’t provide ways to re-render the document, and I don’t think that it was intended to be used that way. Should it, so that less able folk are able to access content: yes.

- All my lecturers used to use ps/pdf for their lecture slides. It worked very well. It got the info across and we could get a copy of the notes. All done.

I feel like the only strong argument here is that it would be nice for the file to render for accessibility and for differing sized screens. That would be nice. Sounds like a great challenge.

Overall this article is a bait article, and I don’t think it should be on hackernews. The stuffed with fluff argument basically boils down to PDF’s are bad because for the PDF’s we’ve looked at “Authors don’t use bullet points”. Cummon! Let’s have some intelligently thought out arguments for a sensible discussion.

I think that you're 100% correct. IMO the general grousing about PDF is the same "get off my lawn" nonsense as people grousing about the ribbon in Microsoft Office.

PDF is not the ideal mechanism for making a webpage or generally browsable thing. It's great for creating portable documents that look and perform the same over time. You can go into an archive in the UK and if preserved, read a legal filing submitted in the 1600s, and understand what it says. Likewise, if preserved, our successors will be able to look at digital PDF/A US Federal court filings in the year 2400 and understand what it says.

We already have content that is essentially lost from the 15-40 years ago due to file format issues.

Other than fillable forms, which is sometimes very important, I don't see how PDF is much of an improvement over PostScript (which came first).

A very simple answer: Xorg has integrated PostScript support which makes rendering .ps files very easy on Linux. Very few tools were ever developed to do this on Windows, to the extent that using Ghostscript ported from Linux is still a common approach. It's still a pain to deal with PostScript files on Windows, and obvious tricks like using ports of Linux viewers that support .ps generally don't work on Windows because those viewers were just leaning on Xorg to do the hard part.

PDF would have a similar problem, but Adobe leveraged their previous work on other products so they basically already had the rendering engine for Windows and it gained traction there.

Keep in mind that both Postscript and PDF were principally designed by Adobe. Adobe designed both because they were intended for different purposes, and this stands today.

Hey, I'd like to read more about this integrated PostScript support for Xorg, can you point me in the right direction please? Tnx

There you go: https://docs.oracle.com/cd/E19683-01/816-0279/dps-91433/inde...

Except it's not Xorg but Sun's own server, and it's not Linux but Solaris.

The feature is called display postscript (DPS), it is basically gone today and was not widespread on Linux, but Adobe maintained a version which they commonly packaged with their products and was a key part of the genesis of the PDF format. These days it is mostly replaced by ghostscript.

Embedded fonts are a big one. PDF lets you embed straight TrueType/OpenType, preserving all the ligatures, kerning, etc. With Postscript you have to convert. Maybe this would be hassle free, but I'd be willing to bet there'd be a lot of edge cases that prevent it from Just Working.

> preserving all the ligatures, kerning

Far as I can tell, most of the time (all of the time?) PDFs just seem to throw out this information, and manually select and place glyphs.

PDFs also serve as a decent interchange format for dropping "signatures" onto a document. These are acceptable in court and in a format that regular business people understand. This is important for digitized contracts that can then also be archived by both parties.

My $0.02 on this:

A work colleague worked on a document signing solution for a client once. Legally, at the time (and I hope this has improved), when a person added their digital signature to a document, that meant that they signed that exact version (read: hash of all the bytes) of the document.

That meant that PDF was sort-of problematic for the use case that the customer required: Giving the customer an A4 version to keep for their documentation was important - but having an A4 version on screen made for terrible scaling UX on mobile and tablet devices.

The fact that PDF is more than just text+formatting in that manner was a real hindrance at that point in time (2017).

(I'd be happy to know if I got any of this wrong after only hearing about it second-hand. This was in Switzerland, if this affects which laws were relevant at the time.).

I think it's been around since the early 2000s, but a few months ago I got very tripped up by this for the first time. I got a PDF I needed to sign and send back (I usually drop and image of my signature and fax or reply). I actually needed to submit a bunch of these forms with varying dates. I couldn't open the PDF with macOS' Preview or any web reader (which happens time to time). I reluctantly downloaded Acrobat Reader. Filled it out, "signed it" and tried to change the date and Save As. It wouldn't let me and it wasn't clear why. I thought I just didn't know how to undo or select and delete the signature because I'm used to PDFs being text + images.

It turns out to be a feature where adding a "signature" locks the document. They suggest if you need to modify it you request a new document.

I'm probably reading the spec wrong, but it might have been added in PDF 1.5 (Aug 2003?)

The signature is cryptographically based on the exact document (and that person's certificate) so you can prove precisely what they signed. That is very much the whole point of the signature feature. It wouldn't be much use if, when you tried to challenge someone later, they could said "oh no, that's not the version I saw, you must have changed it after I signed".

Sure, my frustration is that it a) required Adobe's notoriously terrible software and b) wasn't obvious the implications of what I was doing and c) wasn't reversable/undoable.

I think the concept is great and was just passing along that it existed in PDFs to the parent. Personally, having signed probably 100s of PDFs over the years I had never encountered it. I've only seen the web-based DocuSign. In every case (including this one) faxing the document back was acceptable, which breaks this. I am all for improving chain of trust, but it's not very helpful if the user doesn't understand what they're doing and as someone who likes tech I tend to want a bit more control than most people.

The behaviour you're describing is literally the reason why PDF is still widely used - once you cryptographically SIGN the document you can verify that its content wasn't changed anymore after signing it and both parties can check that.

Incredibly important in many business processes not to mention signing contracts.

In my experience digital signatures are not widely used in “business processes” facilitated by people sending around PDFs. Most are signed with a pen and scanned, or signed by embedding an image. Such signatures have value as a signal of the intent to form a contract, even though it is well known that they do not guarantee authenticity or non-repudiation. Digital signatures don’t add much unless the signer publishes their public key and can prove that a new key with their name on it is inauthentic, and the authenticity of the message cannot be inferred from the surrounding circumstances.

I can attest to the same. I've signed security contracts with government agencies by taking their PDF, opening in in Apple Preview and attaching image of my signature, and sending back. Same with Xournal in Linux. This is how real world, big money contracts get signed. The email history probably attests more to the bonofides of the document than the document itself. It's up to the signers to spot differences visually.

Another tactic is contracts signed by another authorizing action like "your check is as good as your signature language" or "Under the U.S. Uniform Electronic Transactions Act (UETA), this Agreement is executed electronically when both parties agree via e-mail, an Internet web page, or other electronic means and the Client pays the deposit as set forth in..."

A simple email saying I agree is acceptable under US law. No cryptographic PDF features necessary.

Preview's signature import via WebCam makes it even easier.

I'd never heard of Xournal, thanks!

I worked with PDF libraries professionally and we had plenty of customers that requested (and paid) such fuctionality for their business processes.

Also note that those "hand signed" PDFs tend to not hold up to legal scrutiny unless they're also digitally signed.

I'm not sure what jurisdiction you are from but this is certainly not how it works in any legal system I've heard of. In this article published by an Australian law firm [1], the "electronic signatures" routinely used in commerce are clearly distinguished from true "digital signatures" in footnote 1. Digital signatures are only convincing if you understand how they work, and most people executing transactions don't.

[1] https://www.allens.com.au/globalassets/pdfs/insights/xmedia/...

For business, you'd usually use the government's PKI for authenticity.

One problem is that Postscript is Turing complete, so it can be unreliable to parse. Not a great outcome if you just want to view a document.

However, in reality I've often found it easier to write throwaway perl scripts to analyse/modify PS files rather than PDF. Writing a tool to target a set of PS files made by the same process usually isn't too hard unless there is something really unique going on - but it can be a problem generalising it to any random PS file.

PDF is more structured so it can be easier to make general purpose tools, but in my line of work we prefer version 1.4 since the later versions add bloat that isn't necessary for print. It's also usually easier to consider them append-only, it's trivial to add content but editing is a lot harder due to offsets and references.

PDFs work on Windows. Postscript just never had a big Windows adoption rate.

From my understanding, PDF is largely based on Postscript. PDF is to Postscript as HTML5 is to XHTML or HTML4.

I find pdfs easier to read long texts than other formats - I can have a page (or two) displayed at a time, they're always cleanly broken up because everyone sees the same page size, and I can press a keyboard key to move to the next page.

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