There are 3 types of buttons that will appear after articles in PubMed.
If the purple button appears, then full text access to the article is available. Click the button and you should be taken to the journal website where a pdf link will be displayed.
If the button does not appear, choose the button.
The purple and gold button will link out to the UW catalog. When the catalog interface comes up, click the journal vendor name highlighted in blue to be redirected to the article (you may need to browse for the specific issue).
If there is no journal vendor name listed, click on the "Articles (1-2 days)" link. UW Libraries will deliver the article to you via email free of charge.
Note: Vendor buttons will usually present an option to pay for an article unless it is a free service such as PMC (PubMed Central) items.
For additional information, see PubMed help.