Cov ntsiab lus hauv qab yog hais txog qhov feem pua ntawm cov qis thiab qis fibers hauv tag nrho cov plaub thiab plaub uas siv los sau cov khaub ncaws. Piv txwv li, yog tias koj yuav lub tsho down tsho uas muaj 90% dawb duck down thiab 10% dawb plaub, nws txhais tau tias cov ntsiab lus qis yog 90%.
Thaum txiav txim siab yuav ib lub tsho down, nco ntsoov xyuas cov khoom lag luam ntawm lub dab tshos. Ceev faj cov tsho nrog cov ntsiab lus qis dua 50%, vim tias lawv tsis ua raws li cov qauv qis rau cov khaub ncaws uas tau teev tseg los ntawm cov kev cai hauv tebchaws.