Lineweight issue during plotting / printing - please help!!

I have been using Autocad on my windows laptop for the past 4 years now. LAst month, i purchased the new iMac. I copied my old drawing template and plot styles etc over to my iMac.

Heres the problem:

When i plot / print a set of plans etc, the lineweights do not come out as clear as what they do on my old laptop. I dont really know how to clearly explain it, but the lineweights almost seem to come out too similar, however they are slightly different.

I have gone over the line weights to see if they're all correct and the same as on my laptop, and they are. Im using, and always have been using my canon mx870 printer which is supported both by my laptop and the iMac.

Any help would be greatly appreciated, because until then, ill have to carry on using my laptop

PLEASE HELLLLLP!!!!!!!!!

The PC and Mac versions of AutoCAD do differ to a degree; they're two separate OS' made by two separate companies, so it could be a case of you having to entirely re-do the custom line weights as while it's still AutoCAD some functions and abilities may differ between them and cause compatibility issues, like with small details like this.

I'd wait though, as I'm sure someone else will say that's unnecessary and post a better solution.