How do you Increase Painting Resolution / Poly Count

So I've been using the Sims 4 Studio to make recolors of CAS and made some walls.  But mow I want to make some paintings. I've done some with just replacing the art as seen in the photo of the pink roses paintings.  But I also want to make some with custom frames like the Purple Iris painting in the second photo, I made these with a poster but have since made some with the S4S painting template.  The problem is I want a normal sized painting like the ones I made with the poster but I want the images to be clearer better resolution (not blurry). So can I increase the poly count? Will that fix it? And how do I do that?  I assume I export the mesh into blender (before applying my artwork to it) and I think I would go to Add Modifier and use Multi resolution.

I don't know if this is correct also I don't know how to use the Multi resolution.

Please help!





I can't get the photos to insert in this post here is a link instead:
s63.photobucket.com/user/cmvorthmann100/library/Sims%204