What is the fine-grained topic of the following text: Take the double-face embroidered "Cat", representative work of Suzhou embroidery, for example, the artist splits the hair-thin coloured silk thread into filaments-half, quarter 1/12 or even 1/48 of its original thickness-- and uses these in embroidering concealing in the process the thousands of ends and joints and making them disappear as if by magic. Only return the topic.
The fine-grained topic of the text is "The technique of Suzhou embroidery, focusing on the double-face embroidered 'Cat'".