In Alex la Guma's fiction the settings are in South Africa under the rule of apartheid, which began in 1948. Therefore, setting has everything to do with character development in la Guma's stories. La Guma and his parents were all solidly active in the South African civil rights movement. He was born in Cape Town, in a poor section reserved for people of mixed race.
Once apartheid took over there was a division of everything: shops, shopping areas, bakeries, living sector, everything. One part of the town was squalor with specially designed foods and restricted availability of kinds of food. People--characters--growing up in and living in these circumstances are in many senses predetermined in their view of the world, options and opportunities in life and development through life--or through the bit of a character's life as told in a story.
"Blankets" gives a good view of this predetermined character development dictated by setting. Choker is stifled by smelly, threadbare blankets. After he is stabbed, all the smelly blankets he has ever known, and there have been many, pass through his memory. At the end, when the emergency workers take him on a stretcher, Choker is carried away wrapped in a sheet that is pure white and "thick and new and warm."
The tone of the story changes here and a calm descends, implemented by the vocabulary and syntax choices of la Guma, for example, adding "and" between each adjective for the blanket. One gets the sense that if the setting had allowed Choker such thick, new, warm sheets all his life, he would have been a different man. One even gets the sense that in that moment while lying under the "white" sheet, so "thick and new and warm," Choker is redeemed and is made a new man.