unfortunately at the moment I don't have the pictures with me but I was too curios to start investigating that I decided to give it a go without:
Recently I have designed a chocolate mould for bars of the following size (mm): 150 x 75 x 6. Though the bar produced is actually thinner (4-5mm) this should be a relatively standard measure. What bugs me is that once the chocolate starts to set, the bar bends across the biggest length (150) making it not presentable due to the stains on the surface created by the bending as the chocolate gradually "leaves" the mould.
this is answered in a few other spots on this forum. It is a function of the moulds you are using. The chocolate will not bend if you use a polycarbonate mould as they are thicker and more rigid. There's not a lot you can do with the thin moulds you have to stop the mould bending as the chocolate sets.
With regards to your observation on the few spots where I can find an answer, I have spent a considerable amount of hours searching for them and the result was the link that I included in my message above. By all means, if you are aware of any other link that better addresses my question please share it, I'll be very happy to have a look.
Moving to a polycarbonate solution is expensive and before I do so I'd like to make sure that all my doubt are cleared. I have borrowed some polycarb. moulds and I'm going to try them this weekend. Let's see how it goes...