We just put down a custom-size remnant of Stark Whittier Linen in my daughter's room. She picked it herself and I think it looks beautiful with the Farrow & Ball Theresa's Green walls and the bright pink accents she's added in. It's made of 80% wool and 20% polyester so it had only had a slight "new carpet smell" that you typically expect.
When I purchased the carpet, I didn't get the rug pad to go along with it. The experiences I've had with rug pads have been disappointing - they've smelled for a long time and they pretty much disintegrated, leaving particles behind. Looking something like this. In fact, I haven't bought a rug pad since 1992 (seriously - I know the date because I wouldn't buy one for my son's nursery in 1994 )
RugPadUSA offered me a rug pad and they had just what I was looking for: the Eco-Fiber 100% felt rug pad.
It comes in 3 thicknesses - 1/2", 3/8" and 1/4". I went with the 1/4", it works well with the low pile of the Stark carpet and provides just the right amount of cushion. When it arrived and we rolled it out, it had no smell at all - please know that I don't make this claim lightly. Even though this pad was given to me, I am so happy to say it didn't have any odor to it. RugPadUSA notes the following about their Eco-Fiber pads - "are non toxic, odor free, and 100% safe to use on your floors and in your home. Unlike many other felt rug pads, our products are tested quarterly by the Carpet and Rug Institute, a non-profit agency with strict environmental standards. Our Eco-Fiber felt pads also contribute to the LEED point rating system of U.S. Green Building Council for low emmissions, design innovation, and recycled content." Here's a pic of ours before the carpet was rolled over it
and a close-up shot. It is a nice, dense felt with a solid feel underfoot.
While I went with the 100% felt rug pad, there are are a range of options to choose from to meet your exact needs, including rug pads to reduce slippage. All their rug pads come with free shipping, free returns, free custom cutting and trimming and a warranty. They also have a discount to the Trade. Be sure to check RugPadUSA out - I'm so pleased to have this source for the next time I need a rug pad!