To trigger the WebViewer print dialog you can call
To change the printing quality you can set
readerControl.PRINT_QUALITY to a larger number than 1. By default the value is 1 and note that larger values will take longer for the printing to complete and use more memory but will print at a higher quality.
To print a document WebViewer needs to render all of the pages before they are sent to the printer. Unfortunately there is no browser API that allows you to stream the information to the printer which means the memory usage when printing scales with the size of the document.
For most reasonably sized documents the memory should stay within an acceptable range, however with hundreds of pages the usage may be quite large. If you have many documents like this it's recommended that you limit the number of pages that are able to be printed at one time.
When viewing a PDF document directly in Chrome, WebViewer is able to take advantage of the built in PDF renderer to efficiently present the document for printing. There are no memory issues in this case.