After returning from my vacation, I see that we had received our share of Ask an Expert questions that were well addressed by my cohorts while I was away. 

One particular question that was raised related to the different grams of Thinsulate insulation.  The timing of this question was excellent because our Director of Consumer Sales, Joe Hanning, has an outstanding background in outdoor related footwear and he was the person answering these inquires while I was away. 

Please note Joe’s reply that follows here as it has some excellent information in it based on his background that we wanted to share with you.  You can find additional information relating to Thinsulate insulation by going to the 3M US web site checking Thinsulate Insulation Product Information – Boots & Shoes

Consumer Question:

Is there a big difference between 600 and 800 grams of Thinsulate in a hunting boot?

Joe's Answer:

You’ve touched on a topic that I’ve had a lot of experience with over the last decade. It’s a common question here’s my attempt to answer it a simply as possible… 

As you have seen Thinsulate rates their footwear insulations starting at 200 grams up to 1,600 grams. Their Thinsulate Ultra product starts at 400 grams and that’s where the warmth really starts. When it comes to the number defining the insulation, 400 grams is the beginning of their Ultra series, but 800 grams is not double the insulation of 400 grams. Likewise 1,600 grams is not double of 800 grams. Beyond 400, each increment higher is not truly defined by the numeric value, although you will see a slight warmth increase with each step up. 

Now, with that being said, for years, Thinsulate has stated that their 600 gram package is their best package when it comes to quality of warmth for the price. They will not come right out and give temperature ratings simply because each person’s reaction to cold is different.  

And finally, my personal opinion and answer to your question -- we sell more 800 gram boots because that’s what people have come to trust, but I really do not think you are going to see a huge difference between 600 and 800 grams.  

One side bar issue; when wearing boots with Thinsulate Insulation, do NOT wear cotton socks. Cotton traps the sweat on your foot making your feet wet on the inside. Wet feet equals cold feet no matter how much insulation you have. Wear a wool, synthetic or merino wool sock – these materials will wick the moisture away from your foot keeping your fee dry inside of the boot.