Dear Yong Peng,

This might be of interest to you:

Jahn Samia Al Azharia, 2006, Comparative studies on different concepts about
the origin of writing on palm leaf. Botany ― traditional technologies ―
divine teachers. in: Asiatische Studien - Études Asiatiques LX.4: 921-961.
[Abstract: Compound leaves of Phoenix dactylifera were used as tally stick
(Pharaonic Egypt) and for phylomantic (Cumae). The Arabs wrote on date palm
petioles only in pre-Islamic times. Classic writing materials became fan
palm leaves of Corypha umbraculifera and the multipurpose Borassus
flabellifer (wrongly believed ot be a native of Africa). Borassus leaf seems
to have been a substitute for the bee wax of tablets and codices used by
early foreign partners of the Tamil Hindus in maritime trade. Greek, Indian
and Indonesian traditional physico-chemical processing methods for
softening, hardening, preservation and scripts for styles and ink pens were
evaluated. Low-cost palm leaf promoted literacy and “books in mothertongue”
on crafts, healing, lore and religions. Sarasvati, “inventress of
Devanagari” and “guardian deity of lontars” was found to compare with
Athena and Seshat.]

> Is there any pattra manuscripts containing non-Buddhist writings?

In India ? Many thousands.

> I have been thinking for years about where the scriptures monks such
> as Xuan Zang brought to China had gone to.

As I mentioned, they were all destroyed.

> If that is so, where could he had obtained it? There is no known record
> that
> the Chinese adopted this form of documentation/publication, but other
> people under direct Indian influence, e.g. the Sinhalese, may had
> produced their own pattra mss. What do you think?

Of course. I believe some form of pattra mss were in use throughout much of
SE Asia in pre-modern times.

Best wishes,
Stephen Hodge