Who has the study materials of the upholstered sofa lofting division? Or give it to a website of lofting division, thank you!

I am a senior sofa designer/proofing designer for more than ten years. At present, there are only three ways to learn this technology. First, working in a sofa factory, trying to study its characteristics, laws and design requirements. Without the help of the master, self-study is very hard. That's how I got here. It took me two or three years. Second: it is not easy to go to the training class, and the training class is low in charge, so I want the students to work with him as long as possible. If you like your major very much, you can learn it in one year, and there is no foundation. Third: It is also his responsibility to learn from a master and pay tuition according to the regulations, and he must work hard for half a year. A good master can also give you services such as recommendation work and post-guidance for free!

What video textbook can't be learned? It's too abstract.