Jean-Pierre I have some slightly flimsy information on the Pierco frame/foundations. I tried some 10 or so years ago, and inspected a few hundred boxes of the frames used by other beekeepers. On the positive side: a well drawn Pierco frame is a valuable item; it's very strong, the cells are uniform and nearly always worker size. Because of the absence of wood frames, the comb area is significantly larger (I forget the details, you could measure, but my impression was an extra 5 - 10 %, a "bonus" comb in each hive). It doesn't take any labour to put together, and all the frames are uniform. I don't have much experience with their re-use after the first cells are sraped off for whatever reason, I'd think it's significant for honey combs ( and a layer of wax and honey is left), but brood frames sometimes get polished by the bees, and the surface doesn't get re-drawn. (It's not something to plan for maybe, but a bear found the Pierco frames less desireable than wax; some of the plastic foundation were actually still useable after the bear had chewed off the comb,) On the negative side: I found the sharper edges of the frame ends, less comfortable than wood to handle after a while (they never smooth off); Bees seemed to build more "ladder" comb between the plastic frames, perhaps because of the lack of a wood frame barrier, or perhaps because of a shortage of opportunity to build drone comb. Some of this impression came from an earlier version of the frame, maybe the newer one is better. (It might be an idea to provide special frames for drone comb, to focus the colony's drone tendencies. Some might work this into a Varroa trap comb technique) I haven't given this a proper test, but was left with the impression that the frames are less accepted by bees than are wax foundations. It was Ok when the bees didn't have any choice and conditions were great ( eg a swarm) but new Pierco frames added to an existing colony in spring were often ignored, even when syrup was fed. The plastic frame top bar is not as strong or rigid side-to-side, so you may have to change your practice to loosen frames (the Maxant hive tool works nicely, but you have to be careful or you can damage the top of the frame ear.) All in all the frames seemed competant. Each operation would have to do its own economic analysis (one large operator said the plastic frames were less expensive than hiring someone to build wood ones, but there was an advantage to keep good help employed through winter, so he chose the wood). There is also the "plastic" vs "hand-crafted wood" consideration which will differ between people. Regards Kerry