The primary source for these PDFs is Jayarava’s blog and his online repository.
The "seed of knowledge," providing power for speech and intelligence. calligraphy styles Visible Mantra Pdf
If you are a serious practitioner, consider donating to a Shingon temple (such as Henjyoji in Portland or the Koyasan temples in Japan) as a form of Dana (generosity) to offset the use of the PDF. The primary source for these PDFs is Jayarava’s