aspect of subtitles not very clean

hi,

I searched for a solution to my problem, but did not succeed.

I am working with premiere pro cc 2017, and created my subtitles with it, (I didn't choose CEA-708 or 608 but open captions, in order to have more options.)

I went with Arial, regular, 35,  and  3.5 (border)

My problem is.... when I export the file, the engraved subtitles appear in bad quality.

I would like to have that result (this is what I see when I read the srt in VLC) :

and I have this one!

And if I put a thicker edge, the aspect is still not clean :

It's like the white was not so white, the black not so black, and the lines "fuzzy"

I tried to anderstand what goes wrong, I missed something, but what ?!

thanks for helping me You're my only hope (Help me Obi Wan Kenobi) (...)  rhaaa.... too much movies !  sorry

Nelly

(and sorry for my bad english)