What is the difference between...

Excuse me?
Ripstop Nylon is Nylon. That is correct.
It will not shrink or accept finishes, that is correct.
It isn't polyester, that is also correct.

Polyester Dress Lining is not the same as polyester fabric.........

Polyester Dress lining is a material that has not been sized/finished.
It is open weave, will accept dope finishes, can be heat shrunk
and is very close to the uncertified weaves of polyester A/C
fabrics EXCEPT the weights per yard are MUCH lighter.
If you had applied it, you would almost certianly know this
and I would have expected you to agree with using it as a cheap
way to practice on covering structures correctly.

The reason it is called a LINING and not a FABRIC is because
it has no pigments or ornamental "stuff" on it. The fabric
industry calls it a lining instead of a fabric because it is a
semi-finished material. It isn't finished because in its intended use
it would be disadvantageous to have it form a vapor barrier under
the clothing it was protecting...............

ANYWAY.....................

Work on how you present stuff.
I have applied this stuff and it works virtually identically
to uncertified fabrics. The only differences are the shrink
temps and the fabric weights.
--
Have a great day

Scott

none of the other replies got it right.

polyester fabrics go through a process during manufacture to get the
threads to sit into position that involves heating, stretching, and
reheating them to get the threads to conform to the woven shape.

aircraft fabrics are polyester fabrics that have not had the final
heat and conforming process done to them. that is the key difference.

after you glue the fabric to the aircraft structure you go all over
the fabric with a dry steam iron set to 250 farenheit. this shrinks
the fabric into the condition of your store bought poly fabric and in
the process shrinks it by up to 10%. this shrinking is what tensions
the fabric. this is quite unlike natural fibres such as cotton where
the shrinkage of the applied dope is what creates the fabric tension.

I would encourage you to obtain the manual for the Polyfiber process.
This will explain in full detail all the aspects of developing a
competent fabric covering in polyester fabric. Much of the polyfiber
process addresses issues surrounding the impermeability of the
polyester fabric and the lack of adhesion that occurs with traditional
finishes.

My personal belief is that the more recent manuals have been dumbed
down and the original stits manual has the better detail.
My polyfiber manual is dated feb 1993 and this has all the detail.

Stealth Pilot