Maskol vs. Masking Fluid

First of all, I realise Maskol is a form of masking fluid. At the moment, I have a latex based masking fluid (Vallejo’s) but if I just try to apply this to a flat surface it will draw together and not do any form of straight line. Is Maskol better at staying where you apply it?

You will have to “cut” a straight line or any other clean lined detail after the mask has dried with an xacto.