The Airstream factory mattress is 7" thick. Since we already had the sheets on order from from Airstream for their mattress, we could only order a custom 8" mattress (around $635) cut per the Airstream drawing number 703698 titled "Mattress 60 x 75 Queen 'B'" for our 25FB International.
The Rocky Mountain Mattress Company can also make custom sheets to fit their and other's custom mattresses. They also have custom memory foam pillows (about $149 per pair). I was amazed at how much better I slept using one of the memory foam pillows than with a regular pillow.
We ordered the highest thread count sheets and matching pillow cases from Airstream (they are very proud of these sheets per the pricing) and they finally arrived at the end of their stated time frame. They fit the 8" mattress without a lot of slop. We washed them before the first use and they were warm and cozy. We found that the sheets and the Airstream supplied bed cover were enough for warmth when the trailer cooled down to about 60 degrees at night.
We have a very heavy Pendelton queen sized wool blanket for cooler adventures.
WBCCI Life Member 5123, AIR 70341, 4CU, WD9EMC
TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell
2014 31' Classic model 30 twin beds, 50 amp service, 900 watt solar system, Centramatics, Dill TPMS, disc brakes, 16" tires & wheels