Global Scale Modeller

I have a question for the more experienced modellers,

What is the effect of primer on panel lines, especially on really thin panel lines that can sometimes be covered by a coat of paint and thus be useless

Does it make them deeper or does it make them narrower, or does it not change them at all

I would really like to know as I wish to start using primers more, but am worried they will make the panel lines shallow and hence useless.

You should always use thin coats of paint for both your primer coat as well as your colour coats. Two thin coats of primer is usually all you need for most builds. I only use one unless I'm masking.
One thin coat of colour as a base and then another coat to give the depth.
If you keep them thin then any panel line should stand up to a coat or two of paint.

Thanks Coen, might give it a try.