Chimseon(針線) stands for needle and thread, referring to the sewing of fabric such as the stitching or making of clothing, and in broad terms includes all sewn objects.
Besides clothing, bedding items such as blankets, pillows, sitting cushions, and various decorative storing items such as wraps, and cases for writing and eating utensils have also been made with Chimseon.
Chimseon was an important virtue for women in the household. As the craftsmanship of items made in the women’s quarters called Gyubang(閨房) became increasingly acknowledged, the creations are now known as Gyubang Crafts. ---「Chapter 1. Chimseon: An Introduction」중에서

Jeogori

The most basic upper garment of Hanbok, the open front is held together from both sides by Goreum, with no notable differences in shape between sexes and ages. Despite changes with trends over time, Jeogori worn by men are usually lengthy and plain. Meanwhile, Jeogori worn by women used to be lengthy and wide sleeved, but this became increasingly shorter and form fitting. Jeogori is usually decorated with either gilt or embroidery, and children’s Jeogori were also beautifully adorned with multi-colored stripes or embroidery. Jeogori with different colored stripes attached to the sleeves are Saekdong-jeogori.
There are unadorned uni-colored Jeogori(Min-jeogori), Jeogori with different colored cuffs, neckband and Goreum(Banhoejang-jeogori), and Jeogori with different colored cuffs, neckband, armpits and Goreum(Samhoejang-jeogori). ---「Chapter 1. Chimseon: An Introduction」중에서

Various types of fabric were used to make clothing fit for each of the distinct seasons in Korea. As such, spring and fall is made from thin silk fabric, summer from ramie or hemp, winter are made of cotton or thick silk. Leather, fur, felt or wool were also great for the alternative materials.
For summer , hemp or ramie cloth was sewn in a single layer, and for spring and fall, lining was inserted to make multiple layers. Winter was quilted with cotton filling or lined with fur. Equivalent kind of fabric and sewing technique were used for the main fabric and lining.
Nowadays, synthetic materials similar to natural fabrics are used to lower cost and ease maintenance, while the incorporation of Western fabric such as velvet and lace creates a novel impact. ---「Chapter 2. Preparing Chimseon」중에서

Chimseon tools were of utmost importance in the past when clothing had to be self-made. Traditional Chimseon tools include rulers, scissors, needles, thimbles, hot and flat irons, which were stored in sewing boxes, pools and needle cases. Needles were considered the most precious of Chimseon tools, and needles of appropriate thickness were used for various fabrics. Hot irons were heated in braziers and used to fold and press seams or smooth out creases, while frying pan-shaped flatirons filled with hot coal were rubbed over fabric held tight by two people. Starched cloth was pounded on a fulling block with a bat.