I already have 6 yards of .5 oz Silk and was thinking about using it on the inside and M90 on the outside with Climashield for insulation.

Thanks

I am in the process of using 5mm silk for the inside of an 2.5oz syn quilt (am using M50 for the shell).

I think this is a situation where the cons of the material are really minimized.

Probably won't be quite as warm as a quilt with M90 interior as you are replacing a very effective boundary to convection with a so-so boundary layer. But the result shouldn't be as drastic as if the replacement had been done on the shell. Also, resistance to condensing sweat in the insulation should be less for the same reason. But the price and weight are less make this a very good application for silk imo.

Can I ask what type of silk you guys are using? I know people generally use ThaiSilks.com, but I'm confused by the different styles and ratings.

Most people use the habotai silks in 4.5-5momme weight. On thaisilks they have codes 021H and 021F respectively. The 4.5mm is also called "paj" on that site.

I did that and it works well (using 5 mm silk). What I liked in addition to the weight and price is the possibility to dye to the color I want (dye raw fabrics and use more than you will need, the silk shrinks a bit).

The major drawback is probably the durability, I won't use silk for item I plan to use frequently, but this was not the case.

Another thing to consider is your sleep mode. The silk is not slippery enough to turn easily in the quilt instead of turning with the quilt. For me, turning from one side to the other requires to be at least partially awake and hold the quilt by hand.

Regarding the temp rating, there is certainly some loss compared to less breathable materials as mentioned above, but I don't think it is large difference. I've used the quilt down to temperatures usually listed for all nylon equivalent.

habotai 5 momme is what I have