Originally Posted by enarchay
How are they not of the best quality? Could you give me an example? And how do I tell if it is a TOPAZ ebook?
Most Kindle ebooks are AZW, which is identical to MOBI, but some are TOPAZ. This is an Amazon-specific format which seems to be based on scanning paper documents OCR-ing them and using bitmaps of the scanned characters as the font. Many ebooks of older existing books are made from the paper version, but TOPAZ's bitmapped character sets are unique to Amazon. The fonts are not anti-aliased and can include scan artifacts, and the OCR can also have proofreading errors. The ebooks are still readable for the most part. See the attached screenshot from Warrant: The Current Debate by Alvin Plantinga, which is a TOPAZ ebook.
One way to tell if an ebook is TOPAZ is to download a sample and look at it, but you need a Kindle within whispernet range to do this. The other way, that is usually accurate, is that the Kindle Store web page lists the size in KB for AZW ebooks but does not list the size for TOPAZ ebooks. This is probably because TOPAZ ebooks are significantly larger (since they include embedded bitmap fonts).