Besides of separate quality control service, we are offering detailed engineering drawing service if you need. What we meant is that we are very competent of making engineering drawings based upon your rough drawings lack of details or concept design or even photos. Most of store display fixture factories have limited engineer resources and not able to quote or produce the products without feeding them detailed engineering drawings. 

Other obvious benefits for having us to make the engineering drawings are :
1) We are the manufacturer and we know better about Chinese manufacturing and the local equipment. So the engineering drawings that we make should be more feasible and easier for Chinese manufacturers to fabricate the products. 
2) At the large extent, we can avoid quite a bit of raw material MOQs together with Value engineering ideas which could save the overall costs significantly.