How to disable preview for some types (EPS) of files thumbnails in Mac finder?
You need to disable /System/Library/QuickLook/EPS.qlgenerator.  You can rename it to append .backup to that &amp; then rename it back to original to restore it.  

OR you can simply make a copy somewhere else and delete this quicklook generator. 

You may need to run

qlmanage -r 


after that.

The way I reached there is:

mdls /path/to/some/epsFile/pwrdLogo.eps   -name kMDItemContentTypeTree


&amp; then searching the output of 

qlmanage -m 


for  one of these

kMDItemContentTypeTree = (
    "com.adobe.encapsulated-postscript",
    "public.item",
    "public.data",
    "com.adobe.postscript",
    "com.adobe.encapsulated-postscript",
    "public.composite-content",
    "public.content"
)