When people mention "석" (soek) in South Korea, they will think of the Chinese character "石". This word gives the impression of being as thick and hard as a stone.
“가”(Ga) means “to add” in Korean. So this typeface, Ga Seok, is a much thicker typeface than usual typefaces.
This font was inspired by the very thick sans serif font used in Japanese cartoons. The thick strokes fill up the embox, but by giving the right angle at the end of stroke to match with Hangeul characteristics, the font has natural counter spaces with good legibility.
So “ka seok” is not just a thick gothic font, but a font that has a “character” and gives a unique impression.