My family has always used yih8 to mean "to fold", so we would say yih(4) san1 kou3 to mean "to fold clothes" or yih(4) pue6 to mean "to fold the blanket". I wasn't able to find this in the online dictionaries. Instead, they use jih4, and other people in the Gaginang discord server also use jih4. So, I have included both versions here.

I've also asked my soi2 gou1, and it sounds like she has said "yih(8) san1 kou3", so I'm not entirely sure on the tone or whether my mom's family and dad's family say this word the same way. yih8(4) seems more natural to me though.

It looks like there is 揤 yih8, meaning "to press" though I am not sure if my family is using the word for press or if they just pronounce "fold" a little differently.