Courtney Thomas wrote:
What is the best knot that not only will stay tied but is easy to untie
and where can I find an example of how to tie it, please ?

Thank you,
Courtney
You have to tell us whether you mean Polyester, of which Dacron is a
brand name, and is used for all sorts of running rigging, or
Polypropylene which is a much weaker rope, but which floats and is
used for water toys, etc. There is a huge difference in their ability
to hold knots.

While you're at it, you might tell us the application and the size and
type of line. For example, cheap polypropylene won't hold a bowline
at all, but some of the modern forms will.

Also, be careful taking advice from the traditional books, such as
Graumont or Ashley, since both types of "Poly" came into use after
these books were written.