Fireclay tile, one of my favorite handmade tiles, has a 3"x12" tile that is beautiful. The price for this size in the Express or Recycled Clay Body color groups is $30/SF, and the RCB group has matte glazes. I don't know their minimum order, so check that out, but you can order samples fairly easily and their customer service is great. The image below is of the matte glaze Daisy.

Less than 3", but it's matte white & under $15/sq ft.

Daltile Matte Tile

Hi, we are doing a satin granite and picked a very basic Creme Marfil marbel in honed and filled style in 3x8 laid in a mix of herringbone behind stove and subway style elsewhere.

If 4x16 isn't too long, check out the Grid line at Ann Sacks. It's one of their less expensive tiles and the matte finish is nice. For the regular subway size and shape, I'd also recommend Daltile.

Thanks everyone! I'd looked at Fireclay and picked Daisy as a great match but we really don't want to spend that much on our backsplash. Still have a bathroom to remodel and need to cut costs somewhere. I tried contacting Ann Sacks but they never got back to me. Will try again. And also look at Daltile some more.

Emser Vogue has 4x16 Less than $10 i'm pretty sure. They have matte in a few colors. It looks great.