Copy/Paste Ligatures in PDF

[Asinger]

For a couple of years, one of our programmers has complained to me about the presence of ligatures in our PDF documents. He typically likes to copy a section and paste in an email to point out editing that is needed.

I've asked that he simply annotate the PDF and email it to me, which avoids this situation altogether, but since this has come up so much, wondering if anyone has an idea about this problem.

When you copy an area of text in a PDF that contains a ligature, then paste into another app such as the body of an email, the ligature is represented as a black dot instead of the actual character. (e.g. fi is a common ligature found in our docs since we use the word "field" alot).

I've scoured FrameMaker and Acrobat for settings that may control the use of ligatures but find nothing. Does anyone know if there is a way to tell Frame (or maybe it's Acrobat/Distiller) not to substitute ligatures for various character combinations?

Thanks much!

[Asinger]

For a couple of years, one of our programmers has complained to me about the presence of ligatures in our PDF documents. He typically likes to copy a section and paste in an email to point out to me editing that is needed.

[thomas bro]

This is not really a FrameMaker issue, but rather a font issues and cross platform.

It is not possible due to the fact that the fi (or any other ligature) is a fixed character 'pair' somewhere in a font. Basic old TrueType and Type 1 font have 256 places whereas OpenType have more.

Not all font support ligatures. So if you were to paste a ligature into a font that does not support you would either get squares, question marks or other funny looking characters. If you paste the ligature pair into a font that does support ligatures you might get lucky. It all depends on the software you are using. FrameMaker for one will not accept it.

keep smiling
thomas

[Bill Swallow]

Are these OpenType fonts?

See <http://partners.adobe.com/asn/developer/opentype/gdef.html> and <http://partners.adobe.com/asn/developer/opentype/appendices/ttochap1.html> and <http://www.adobe.com/support/techdocs/12f6e.htm>

[Arnis Gubins]

IIRC, the fi and fl ligatures are done automatically on Mac and unix
systems by FM since these are in the standard encodings for those
platforms. In windows, these ligatures are not found in the standard
font encoding, you would have to use an expert font to get them.

When copied on Windows platforms, these should come across as ANSI
codes 222 for fi and 223 for fl. So a simple search&replace by your
engineer on the ANSI code and replacing with the appropriate
characters should do it.

[Asinger]

Arnis,

I am a little bit confused - this isn't an area of great understanding for me. It seems like what you are saying about the ligatures happening automatically is a contradiction to what Thomas explained, if I am understanding each of you correctly. Perhaps I am not (it won't be the first time!).

Is it your experience that FrameMaker is going to use the ligatures regardless of the font I am using and that PDF files I create from the Frame docs will then also contain those ligatures? Therefore, I have no control over their existence in my PDF documents, though there are ways to work with it, such as you suggested.

I use Frame on Mac OS 9.0 and also Distill on that machine. The programmer in this scenario opens the PDF files I generate on a Mac also, and performs the copy and paste. I receive the email he sends on Windows, however, I don't think that is an issue, since he sees the ligatures as soon as he pastes the text copied from the PDF on his Mac.

By the way, this programmer said he has done extensive work with fonts, and that it must be FrameMaker or Acrobat/Distiller that is "choosing" to use ligatures as opposed to using the two individual characters within the font set that make up that ligature.

As you can see, I am getting different information and just not sure which way to go! But I do appreciate everyone's input.

Bottom line is I asked that he simply annotate the PDF and email back to me and then this isn't even an issue. But mysteries are meant to be solved!

Thank you to everyone, Arnis, Bill and Thomas.

[Asinger]

Bill,

I'm fairly illiterate about font types. What I can tell you is that I generally use only two different typefaces in all manuals, Helvetica and Palatino, and I have an Adobe suitcase for each (the little suitcase icon with an A on it). Is there a way that I can determine more about the type of font this is?

Thanks.
April

[Asinger]

Thomas,

I guess my question to you would be, if a font/typeface contains all alphabetical characters A-Z in upper and lower case, and it also contains ligatures in the extended character set, why, if I am typing an "f" and "i" would the ligature be used instead of the individual characters in that font set?

Always smiling
April

[Arnis Gubins]

>FrameMaker is going to use the ligatures regardless of the font I am using

On a Mac and unix system only. AFAIK, this is hard-coded for the fi
and fl. I also checked some PDF documents generated on a Mac. Words
with fi and fl ligatures do copy properly on a Windows platform using
Acrobat 5.0.5. It's my understanding that current versions of Acrobat
(5.0.5) take care of the ligature mapping back to proper characters to
satisfy Accessibility requirements. So my previous suggestion can be
ignored.

What version of Acrobat or Reader is being used that creates these
problems?

[Dominic Hurley]

I thought that ligatures were optional and were set in preferences. But then I'm not on a Mac so I may well be wrong.

[thomas bro]

When using InDesign 2.0, Times as a T1 font (not an expert derivate) that does not have ligatures defined you get a PDF that has a visible and printable ligature (again just taking fi as an ex.). When this ligature is copied from the PDF to anywhere on the Win platform it is pasted as two questionmarks (??). Even back into InDesign.

This means that it is NOT at a fixed position as described by Arnis.

keep smiling
thomas

[Arnis Gubins]

A couple of things.

The fi and fl ligatures are only activated when "Pair Kern" option is
selected in the paragraph or character designers on Mac and unix
platforms.

The latest releases of Acrobat and Reader can decipher Mac encoded and
unicode ligatures back into the proper character components. This was
a requirement to meet U.S. Accessibility legislation (Section 508) for
text readers and so on.

[Asinger]

I think that the reader the programmer is using to copy the text is likely v4.x. I have both v4.x and 5.x (not sure of exact release). So, it sounds like there are two routes. A) he can upgrade to v5.x, or B) I can disable Pair Kern. I'll try each to confirm the results, but ultimately I think everyone in the office should be using Acrobat Reader 5.x.

Thanks to everyone for your assistance. I'll let you know how it works out, in case anyone is taking notes!

Happy Valentines Day.
April

[Asinger]

Just to clarify, the versions of Acrobat Reader I was using on my pc in the test I detailed earlier were:

Acrobat 4.0
Acrobat 5.0.5

Thanks!

[Asinger]

Bill,

Thank you for these links. This info is a bit over my head, but I've saved as PDF docs and will let the programmer here in our office who was having the problem with copying and pasting from PDFs read them. Perhaps he'll find something useful. I'll also read them more carefull to see if it mentions how I can identify whether or not I am using Open Type fonts.

Thanks for you time.

[Asinger]

Dominic,

That is what I was hoping when I started out, but I have scoured all prefs and settings that I could find, and found nothing that seemed to affect the use of ligatures by Frame.

However, I think that Arnis is correct that the Pair Kern setting in the Paragraph Designer for the format used has something to do with whether or not ligatures are used.

Thanks for your input.
April

[Asinger]

Well, interestingly, I have gotten quite mixed results. I created a simple paragraph with lots of "fi" and "fl" words. The Paragraph format applied had Pair Kern enabled. At first attempt opening this in both Acrobat Reader 4 and 5, copy and paste to an Outlook email message on Windows, I got the ligatures with text copied from both reader versions. Then I disabled Pair Kern in the Frame doc, PDFd again, opened in v4 and 5, copied and pasted, and did NOT get ligatures in the copy from either version of Acrobat.

To try and force it to happen again, I opened the old PDF again, the one from the Frame doc with Pair Kern enabled. Hmmm, no ligatures this time, same PDF!

I actually created a new Frame doc and repeated the process, but in no case could I produce the ligatures when copying and pasting from the PDF doc. So I'm kind of stumped. Is their possibly some system setting on my pc that was set the first time I used Acrobat v5 so that now both v4 and v5 work fine?

I don't use Outlook on my Mac, so couldn't test purely in the Mac environment, however, even yesterday I could easily produce the ligatures by opening a PDF produced on my Mac on my pc and doing the copy/paste to Outlook.

I could say the problem is now resolved, because it simply isn't occurring, but I think I know better than that!

If anyone has more to add, that'd be great. But please don't spend too much more time on this. I definitely have a couple workarounds that can be used, and I actually prefer that people submit changes to me via annotated PDF, not by pasting from the PDF into an email message.

Thanks again!
April

[Asinger]

I suppose I appear to be having a discussion with myself this morning! Just wanted to add that I have confirmed I am using only TrueType fonts. I got this information from the Paragraph Designer. Never noticed that this information was there before. Guess I just get used to seeing what I am familiar with.

Thanks

[Asinger]

Well, I feel rather dumb at the moment! Originally I was focusing on Acrobat Distiller to solve the ligatures "problem". I had searched the online help. Then when I tried searching my Frame online help, for some reason help wouldn't come up (still won't, I have to work on that). The printed manual wasn't around. Now I located the printed manual, and lo and behold, page 95 (v6.0) talks about Pair Kern and ligatures! "Pair Kerning also turns on ligatures..."

So I think I shall just turn Pair Kern off, as so far, I don't see any negative result in doing so.

I hope I didn't totally waste anyones time. I appreciate all the input.

Thomas - are you still smiling?

Thanks!
April

[thomas bro]

April,

I am always smiling. Not only because of forums like this. We would all be bad off if they didn't exsist. Eh?

Other reasons for smiling. Honestly there are thousands. Just look out of your window, listen to the birds, read a good book, caring for your loved ones, hoping peace will prevail and discussing small matters like ligatures. It's all in your mind.

so still smiling
thomas

[Asinger]

Agreed. Take care.
April

[Jeanie Shoemaker]

Never mind...I see that this is covered in another post.