Stiffness of finished Carbon Fiber part

I have a finished CF sample, a common single-ply weave, that exhibits
extreme stiffness, 'thin-ness' and is very lightweight, it looks dry. I have
molded a part using a similar weave, single ply, and do not get the same
stiffness. I can easily deform the finished part with a press of the thumb.

I am not sure whether this is due to the epoxy type or my humble curing
process. I'm using Fibre Glast System 2000 and 120 minute hardener. I let
the part cure for 12 hours at 110 DegF. The instructions on the can discuss
postcure at 200 DegF and the resulting 'service temperature'.

If it is an Epoxy issue, pls describe and recommend an alternative product.
If it is a postcure issue, when does 'postcure' begin - after my 12 hour
cure cycle? - which was loosely calculated based on instructions on the can.

Any advice appreciated.