To achieve light, crisp and flaky layers, I recommend using a combination of shortening or lard (in the oil dough) and butter (in the water dough). I do not recommend using only butter or margarine for both. This may over-enrich the dough and taste too rich (unless you enjoy a rich pastry). For this reason, I use CRISCO butter-flavour shortening over regular shortening. Lard is the ideal fat to use (you won't even smell or taste it) but may be more difficult to source depending on where you live. The butter flavour shortening strikes a taste-texture balance that works perfectly for Chinese puff pastry.