去年八月在香港理工大學《恢弘經典－香港男裝長衫製作技藝及非物質文化遺產傳承研討會》分享過中式男裝的包骨工藝。當時沒有製作過程的照片，只能透過圖解略說製作過程。再做一次芝麻紗男裝單長衫，製作期間不忘拍照存檔。現在整理研討會當日分享的資料，以及製作期間的照片，保留一個「包骨」工藝比較完整的記錄。
鱔骨縫，中式包骨工藝，一般用於中式服裝用料較為輕薄的單衫(無夾裡衣服），主要用於中縫和接駁袖片，大裁褲拼合褲襠也有用上(注一)。這種將四層布料－兩層面布、兩層縫分縫合的工藝，令單薄的衣服接縫變得異常牢固，不易變形或開裂。縫骨只闊唐寸1分（約4毫米），乾淨俐落，裡裡外外都很好看。若然夠膽大心細，縫骨可小至只闊半分（約2毫米）。這種工藝，常見於明清存世衣服，在民國時期的男裝單長衫仍能見到。後來可能由於它費時、費工夫，以及不再流行中式單衫，它漸漸退出了歷史舞台。
注一：《國服製作（四）》馮綺文編著，台北：格致圖書有限公司，頁121，內有製作教程。《繡羅衣裳》牛犁、崔榮榮著；漢族民間服飾譜系，崔榮榮主編，北京：中國紡織出版有限公司，2020年1月，頁145。
Eel’s bone seam (Shan1 Gu3 Feng2) is a traditional Chinese seam used in stitching clothes without lining. It was commonly used during Ming and Qing dynasty, until the mid-20th century. Its appearance is quite similar to flat felled seam or French seam, but the construction method is quite different. The finished seam is extremely narrow, usually measured between 2 to 4mm.
The front and back centre seams are eel’s bone seam. The rest of the seams of this transparent cheongsam are trimmed to the same width as the eel’s bone seam, which is 4mm wide.
長衫設計／Cheongsam design by：Impression of time
3-4mm wide eel’s bone seam
Close-up photos of Eel’s bone seam on men’s cheongsam in the 1930s-1940s. Photos by Xiaohongshu user 746688282.
Two pieces of fabric, right side together, fold the seam allowance, and stitch all 4 layers of fabric together.
Trim the excess seam allowance.
Fold the stitched 4 layers once again, so that the raw edges of the seam allowance are hidden.
Hem stitch the folded part onto the back of the fabric.