Frequently-Asked Questions

If you only need to view or print PDF documents, then Reader should work for you.  If you need to create documents, apply digital signatures, re-order pages, or add comments and markups, then you will need the full version of Acrobat or a similar product that has these capabilities. 

If you are using third-party plug-ins to add functionality to Acrobat, they may or may not work with Reader.  Plug-ins that copy, save, or create PDF files or that create digital signatures, can only work with the full version of Acrobat.  Other plug-ins that only provide viewing functions or signature validation may work with Acrobat Reader as well.  

For information about using the Banjo digital signature plug-in or the LineScale measuring plug-in with Acrobat or Reader, see the Products page.

Where can I get the free Acrobat Reader program?

The free Acrobat Reader can be downloaded from the Adobe website here.

Where can I purchase the full version of Acrobat?

The full version of Acrobat can be purchased on the Adobe website here, or it may be purchased at a number of on-line stores.

The lines in PDF files look heavy and uneven on my screen.  I can't see any detail unless I zoom way in.  What's the matter?

Acrobat and Reader have a setting for "smoothing" that will make the images look better.  Under the Edit menu, choose Preferences.  Select the Display tab and check the boxes for Smooth Text, Smooth Line Art, and Smooth Images.  

When smoothing is enabled the display regeneration may be slower on some computers.  It makes a big difference in visibility, though.

How do I make a PDF file?

PDF files are most commonly created with a special printer driver that installs on your computer.  When you print to this printer, a PDF file is created in place of a hard copy.  

How can I send PDF files to consultants or clients?  Can they be viewed in a web browser?

PDF files can be attached to an email message or uploaded to a website for viewing.  PDF documents can incorporate built-in compression, making utilities such as WinZip unnecessary.  When PDF documents are to be included on a web page, they can be saved in Fast Web View mode which allows the first pages of a multi-page document to be viewed before the entire file is downloaded to the user's computer.  This speeds up viewing considerably.  

When the free Reader program is installed, a plug-in to the web browser is installed as well, allowing online viewing of PDF files through the browser window.

How secure is a PDF file?  If I send a PDF of a drawing to someone, can they turn it back into a CAD file and change it?

There are multiple security options built into the PDF format.  Depending on the PDF creation and editing tools available to you, it is possible to encrypt the file with a password, to copy-protect it so that information cannot be extracted, to print-protect it so that users cannot print the file, and to protect it against changes.  A digital signature can also be added as verification that no alterations have been made to the file.

A user who has full access to a PDF file (i.e. an unprotected file, or a password-protected file for which the password is known) will still have difficulty extracting usable data.  Although it is possible to turn the vector data in a PDF file into a DWG, all layer, scale, and line weight information would be lost and all text would most likely be converted into vectors and lose its association as text.

Is PDF a raster format or a vector format?

PDF supports both raster (bitmap) and vector (line) formats.  When a PDF is created by printing from a vector-based application such as AutoCAD or an illustration program, the resulting PDF contains vectors describing all the lines, arcs, and shapes in the drawing.  The output can be scaled with no loss of resolution, and viewers can zoom in on the lines in the drawing without seeing any 'jaggies".

If a scanned image is converted to PDF (such as an existing paper drawing that has been scanned) then the resulting PDF image is a raster image.  Zooming in will expose the individual pixels.  

Raster and vector formats can be combined in the same document if some pages are printed directly and others are scanned.  The formats can also be combined on the same page, as when a raster image is imported into a CAD file and then printed along with vectors on the same page.

Is the scale of a drawing preserved in a PDF?

If you print to scale, then that scale is preserved in the drawing.  When printing, use the same scale setting you would use for a scaled plot to paper.  When the PDF file itself is printed, the user will have the choice of reducing it to fit a certain page size or printing it at its full size.  If it is reduced to fit then of course scale will be lost, but when printed at full size the output from PDF files is as good as the accuracy of the output device itself.

How big are PDF files?

That depends on what is in them and on what type of compression is used.  A typical 24" x 36" architectural drawing, such as a final floor plan with a title block, many notes, dimensions, and symbols for construction, is generally about 650 KB.  A simple schematic floor plan of a typical house might be 50 KB.  A press-ready color brochure with high-resolution scanned images can be 10 MB or more.  A file with just a few small raster images using good compression can be as small as 90 KB.  A typical letter is about 40 KB.

How do PDF files compare to HPGL (PLT) files or DWF files?

Although all these formats share some similarities, there are important differences, in terms of both features and standardization.  

With more than 500 million copies of the free Reader program installed worldwide, the PDF format is by far the most widely accepted document format.  Most clients and consultants already have Reader installed on their computers, so they will not need to download anything else to view PDF files that are sent to them.

PDF is a standard in the printing industry and is also used extensively by various departments of the U. S. Government, including the Army Corps of Engineers and the GSA.

Can my office plotter print PDF files?

Yes, you should be able to print directly to your plotter from Acrobat or Acrobat Reader.  Just choose the Print command under the File menu and choose your office plotter as the output device.  

I send my plot files to a print shop.  Can they print PDF files?

Most print shops can print PDF documents in one of two ways.  Either they can send the files to a plotter through Acrobat or Reader (the same as you would send them to an office plotter) or they can use specialized plot-management software that can interpret PDF files directly and bypass Acrobat.  

Will my pen settings and line weights come out right in a PDF?

Line weights and colors are embedded into the PDF document, which is completely self-contained.  No separate "settings" file is required as is sometimes the case with HPGL or PLT files.  What you see on the screen in Acrobat is what will be printed.  

If a large-format PDF file is printed on a desktop printer (such as 11x17 or 8.5x11 format) with the Shrink oversized pages to paper size setting turned on, then all line weights will be reduced along with the drawing to maintain readability.

How can I print just a part of a large drawing on a smaller piece of paper?

Use the Graphics Select Tool to select the part of the drawing to be printed.  Then choose Print from the right-click menu or from the menu bar.  If  the Shrink oversized pages to paper size setting is not enabled in the print dialog box, then the selected portion of the drawing will be printed at full size.  If the selected area is too large to fit on the printed page, it will be cropped or you can enable the Shrink oversized pages to paper size setting.

How do you create a full set of drawings in a PDF?

The ability to create multi-page documents, complete with bookmarks and hyperlinks, is one of the most powerful features of the PDF format.  Drawings can be collected from various consultants (even if they use different CAD programs) and combined into one PDF document that can then be organized with bookmarks to simplify navigation.  If some consultants do not have the ability to create PDF files directly, their drawings can be scanned and saved as a raster PDF.  

Different page sizes, graphic types, or color and black and white images can be freely combined in a document.

In order to perform this type of editing on a PDF document it is necessary to have either the full version of Adobe Acrobat or one of the less-expensive (and less capable) editing programs such as Jaws PDF Editor.  

Is it possible to redline or comment on PDF files?

Yes, this feature is provided by the full version of Adobe Acrobat.  Freehand or vector-based lines and shapes can be combined with typed comments, all of which are readable with the free Reader program.  

PDF-based redlining is a great way to save time and money on checksets.  Design team members can email their PDF files to each other for review and comment, and then pick up changes for the final production drawings without ever printing anything out on paper.

More information

FAQ

The PDF Format

Integration with CAD software

Resources