Many times people may wish to save an article they've come across on the Web, in order to reference it later, when they may be offline. There are several ways you can do this, including taking screenshots, saving the page as a Web archive or HTML source, or printing to PDF. Each of these options has its benefits and drawbacks, but only one will allow you to create clean and nicely formatted PDFs of the article you are viewing.
Saving Web pages
The first option is to save the Web page of an article you are reading. You can do this by choosing "Save As" from the File menu in Safari, and then selecting an option to either save it as a Web Archive or as Page Source.
If you save the page as a Web Archive, Safari will package the source code for the page along with any images, so the page will load the same way when you open it. This option is great for preserving the contents and formatting of a Web page, but it will also include elements such as ads and navigation bars in the document as well. If you save the document as Page Source, you will be able to view the text of the page, but its styling and formatting may be off, and it will not include any pictures or graphics if you are offline. This is a convenient way to grab the text of a Web page in a small file.
The second option is to use screenshots, which can be done either with the Grab utility or with keystroke combinations (i.e., Shift-Command-3) and can be used to capture the parts of a Web page that are shown on screen. This is perhaps the quickest way to save what you are seeing, but the resulting document is rather limited. For one it will be at the screen's resolution of 72dpi, making it grainy when printed. It also will include various window and system interface elements (other applications, the dock, the system menu, etc.) and will only show what is currently being shown on the screen. The document is also a rasterized image, which means text on it will not be indexable for searching or be selectable for copying or future editing.
Print to PDF
The ability to create a PDF out of any printable document is a convenient feature that is available in most modern operating systems. The PDF technologies in OS X include this ability right out of the box, but you can also take advantage of Adobe's "Print to PDF" feature by installing Adobe Reader (convenient for if you have Boot Camp or use virtual machines).
In order to print to PDF, you just press Command-P or otherwise invoke the print dialogue box in OS X, and then choose the option to save the file as a PDF from the "PDF" menu that is usually located in the lower left of the print window.
While this feature allows an indexable and nicely formatted PDF to be created, it has some of the same drawbacks as saving a Web archive or Page Source in that it will include ads, headers, footers, and other page elements that you might not want.
Making a clean PDF
To make a clean PDF of an article, you will need to find a way to strip out the unwanted page elements before printing it. Luckily Safari has this option with its "Reader" feature, which is built to show you the basic article you are reading by removing flashing ads, pictures, navigation bars, and links to other articles. In most cases, as long as a page is formatted in HTML to show a single article, Safari's Reader will isolate it from the rest of the page for you.
To invoke the Reader, either click the "Reader" button that will appear in the Safari address bar, or press Shift-Command-R when viewing an article (see our article on the Safari Reader for how to do this).
With the Reader open, if you hover your mouse at the bottom of the Reader window you will see options to navigate, zoom, or print the document. Click the print button and when the print dialogue appears select the option to save the print job as a PDF. The resulting PDF document should be cleanly formatted, and should include the article's pictures without including ads and other unwanted features.
The only drawback to using the Reader is that many times articles will be shown on multiple pages in a Web site, in which case the reader will only show one page at a time. However, if you print each page to PDF, you can then use Preview to combine them using cut-and-paste methods, and thereby save the article in its entirety.