This sharing may come a bit too late since the Chinese seventh month is over. Nevertheless, I would like to share this excellent booklet that covers in details of the Theravada Buddhists’ concept of merit sharing as well as the offering of food to the departed loved ones. I personally subscribe to the concepts described in it since the author have done in-depth research on the historical aspects and made frequent references to the Pali scriptures to substantiate his points. Hence, the booklet serves well as a blueprint for Buddhists who wants to follow the correct practises, as close as possible to what the Lord Buddha actually taught. It also discourages the burning of paper offerings which has nothing to do with Buddhism proper.
Link to the booklet: http://sasanarakkha.org/ebook/Honouring%20the%20Departed.pdf