wall reflection prefrences

hey guys hows it goin. setting up a closet grow in my new place and lookin for any good tips and what not for best results in terms of light reflection. just a bit of a preface, done a big room grow before and we used white posters board for the white cause they were cheap and it was a rather sizable room to cover. today i just finished lining the walls/floor with tarp and curious to see what type of options would be good. im lookin to do a 5-8 guys max and the closet is (from memory) i beleive 3x6x11. thank for any tips =))