This is a new version of HLSL settings I have been using recently and I find them much more "accurate" than my previous settings found here:
To use this simply enable HLSL in your mame.ini by setting hlsl_enable to 1 instead of 0 and dropping this raster.ini file into your \Mame\ini\presets folder. Backup your old one first just in case you do not like this one.
I do not take any credit for these settings at all. I got these from the youtube channel Big Blue Frontend and his custom 186 version of Mame he uploaded.
As always with shaders there are several factors that have an effect in how they look such as display type (TN vs IPS) size and resolution and of course personal preference.