hi John, this thread is made by Kupfer it is AVINO E 11/4
Avino E is a multifilament polyester thread. Polyester won't swell. Amann Serafil and Ariadna Tytan are similar products. Can't find 11/4 on the Kupfer homepage http://www.naehseiden-kupfer.de/produkte/polyestergarne/avino-e/
. The closest equivalents listed are 11/3 and 10/3. 20/3 (138 in US-designation) can still be machinesewn with size 140 (22) needles. After that it's professional territory.
Thread that can swell typically needs natural fibres like hemp or cotton. To combine the tensile strength of polyester with the ability to swell of cotton you would chose corespun thread with a polyester core and cotton surroundings like Kupfer Intra or Amann Rasant.
For a tensile strength comparable to multifilament thread a corespun thread must be thicker, which means bigger needle holes to start with. The cotton then can function as a wick, actually sucking water through the hole due to capillary effects, and ultimately the cotton will decay due to UV-radiation, moisture and friction, leaving the big needle holes. I once talked to an Amann technician about this, because I wondered why they didn't mention the swell effects in their advertising. She said, they had read about supposed swell effects in the internet but have not been able to confirm the effects in the lab. Amann recommends WR (water repellent) thread to avoid the wick effect and additional seam sealing if the holes are expected to be watertight.