The Messenger of Allah ﷺ only forbade garments made entirely of pure silk. Ibn Abbas said, "As for silk used in the warp threads or as a border trim, we see no harm in it."
حدثنا مروان حدثنا خصيف عن عكرمة
إنما نهى رسول الله ﷺ عن الثوب المصمت من قز قال ابن عباس أما السدى والعلم فلا نرى به بأسا
Its isnad is sahih. Abu Dawud, Tabarani, and Hakim narrated it, as in al-Muntaqa and the commentary on it, 711.Al-musmat is that which is entirely silk, with no cotton or anything else mixed into it. As-sadi, with a fatha on the sin, is the opposite of the weft, being what is stretched lengthwise in a fabric, and it is well known. Al-alam is the pattern of the fabric, or its markings at its edges.It will come again in abridged form at 2858 and 2859, and at length at 2953.