In some areas, particularly where rotting vegitation keeps stiller waters fairly warm year round, brine wool grows all year, but most such wools are of the feltable sort rather than the finer long strands. Where there are moving waters, brine wool dies back each winter, remaining on the downstream side of rocks as brown or gray nodules about the size of barley grains. When the waters have warmed in the spring (usually by late March), the brine wool begins to grow again, and it generally continues growing through mid-November. A given streamer will continue to gain length and diameter so long as no more than about two thirds of the streamer is taken; in undisturbed areas (particularly in waterfalls), brine wool streamers up to five feet in length have been discovered.
Generally, the gathering begins when the brine wool has reached a length of six inches, and continues until dieback in the fall makes the brine wool brittle. In Triel, tradition dictates that when gathering brine wool on "common" lands, one ties a cord dyed red with an unstable dye near each group of streamers to indicate that it has been disturbed recently; when die has faded entirely, the brine wool streamers have likely recovered enough to be harvested from again. In some areas, there is informal recognition of a "claim" by a given person to a given stream or pond, making it possible to wait for the brinewool to grow to greater lengths before harvesting it: these long-staple wools (two feet or more) may be spun into a very fine thread which is used both in lace making and to for lighter cloths.
After harvest, "streamer" brine wool is washed, sorted for length and color, and then "aged" for one to four months while it dries -- whether drying should be done rapidly in the sun, or slowly in the shade (but away from the weather) is a matter of some dispute. The dry wool is then combed and spun. "Mat" brine wool for spinning is cut into smaller pieces, then washed, aged, carded, and spun into thicker yarns. For felting, the brine wool mat is soaked for at least a month (changing the water every three days), then pulled to an even thickness, and tied to a frame for "curing", which involves alternately drying, soaking, and beating the felt until it acquires the proper texture.
Brine wool occurs naturally in in various shades of brown, gray, and green, and occasionally in dark grays approach black, and most of it is left in these natural shades. However, it can be bleached to near white (a long, involved process), and there are two dyes, one blue and one yellow, which will take on brine wool and not run onto the wearer's skin or other clothing. One family in western Triel grows mat brine wool in ponds built for the purpose, and has produced some very light colored mat brine wool by (they claim) controlling the mineral content of the pond; as no one believes that they would have gone to the trouble of bleaching mat brine wool, that claim is generally accepted. However, no evidence has been seen to date of the "naturallly pink" wools they claim to be perfecting.
The most noteworthy property of brine wool is its ability to carry mosture: if you are caught out in the rain in brine wool clothing, you will rapidly become thoroughly soaked, but you will also dry in about twenty minutes once the rain stops, as the water simply drips out of your clothing. Tents of brine wool felt can be very practical in areas of short but frequent rains: so long as nothing within the tent touches the roof, the water will all follow the fabric to the ground, protecting the occupants, and the tent will be dry enough to pack within an hour of the rain's end. The restive sleeper, however, may become uncomfortable, as if he rolls against the side of the tent, he will awake in a puddle. Light-weight brine wool fabrics are well-received in warm areas, both where there is frequent rain and by those who work near water, and lace made with brine wool is almost the only sort that can be made presentable without cleaning and pressing if the wearer is caught in the wet. Heavier brine-wool fabrics are quite warm, even when wet, but many prefer to attempt to stay dry if the rains will be long or chill. In the coldest climates, there is the additional difficulty that permitting brine wool fabrics to freeze while they are still wet can damage the fibres, reducing the useful lifetime of the fabric.
In Triel, brine wool fabrics are particularly favored for children's wear, as they will take frequent muddying and washing remarkably well. And of course, no respectable brine wool gatherer would wear anything else to wade in the streams and ponds during the gathering season.