Why is a larger size margin of error indicated for knit items?

Looking at the numbers first, it is 1-2cm. Below MOONDAL's size charts, a notice is attached stating that this degree of margin of error may occur depending on the measuring method^[1]. However, when moving on to knit items, this number increases to 2-3cm^[2], and in some items to 3-4cm^[3].

This is due to the knit structure. Because knit is a knitted fabric made by interlacing yarn into loops, it stretches when pulled and returns to a certain extent when released. Therefore, even when laying the same garment flat to measure, the reading on the measuring tape varies depending on how much it has been smoothed out. This is why a larger margin of error is set specifically for knit items.

There are also cases where variations are separately specified for reasons other than the measuring method. For some items, it is added that the actual measurement margin of error may vary depending on the color even for the exact same item^[4], and for the Raw Crumple Top in Oatmeal, it is noted that a difference of around 1-3cm may occur for each individual garment due to the characteristics of the manufacturing process^[5].

hmmm, the number 3-4cm is closer to meaning that the value may fluctuate that much even if measuring the same garment 2 times, rather than meaning that the garment was made that much larger.