RTV Brush on mold vs liquid latex mold? pros/cons?

[airair]

I'm deciding on whether to do a rtv brush on mold or a liquid latex brush on mold on a part.

Can anyone give me the pros, cons of each?

I am going to cast polyurethane polytek pt flex 85 rubber once ive made the molds.

Which is the longer lasting and better?
And which is generally cheaper?

thanks

 

[Fireball Joe]

Latex will be cheaper but rtv silicone will last longer. A lot depends on the size and detail of the part you want to reproduce.