Reflective highlights can distract from an art piece, so I recommend a matte or satin paper. Acid-free, 100% cotton, and a-Cellulose papers generally have a longer life and are considered more archival. Metal (aluminum with dye sublimation printing) is a high-end, modern look, with the satin options I offer providing the lowest sheen. 

My personal preference of the four papers I've selected are, in order:

1. Smooth Fine Art Paper III - Acid Free - Epson Hot Press Bright White: 16 mil, 100% Cotton, Bright White. Hot press paper is generally smoother than cold press paper, and the surface of this paper is particularly smooth.

2. Smooth Fine Art Paper - Acid Free - Moab Entrada Bright Raga: Bright White. 290 gsm, 100% Cotton.

3. Fuji Deep Matte Velvet - A deep matte paper, with a nearly imperceptible sheen. True blacks are a bit lighter with this paper, which does not stop me from recommending it. This paper has a beautiful but subtle velvety look and feel. This is not an acid-free paper.

4. Satin Fine Art Paper - Acid Free - 300 gsm, 100% a-Cellulose, Satin Finish. Extremely Deep DMAX, a measure of the depth of blacks achievable.

The Fuji Deep Matte Velvet is the least expensive option, with the other three paper options essentially equal in price. Metal is the most expensive option.

If you prefer or require a paper type that you do not see here, please contact me. It is likely that my printer offers a paper that will meet your needs.