Hi Tangamoon,
Sorry not sure I understand the question. We've a sail stack with lazyjacks attached, and it is stiffened fore / aft with a 10mm round fibreglass batten.
Is that what you you were asking about?
JOHN
Mine has a fibre glass rod in three sections which fit into each other. Approx 10mm in diameter, either side of the boom in a fairly tight full length pocket.
Mine has one very long flat fibreglass batten in each side of the cover approx 50mm wide and the length of the cover. Slips into a pocket in the cover and is secured with velcro.
Flat sail battens, which should be a close fit in the pocket to stop them lying flat and bending, are a good method. My own sailbag has plastic tubular stiffeners, which have sagged downwards at the front end due to lack of support.
Ours has round sail batten with plastic ends. Very stiff and very successful. I will try and remember to take a photo of ours. They are lying on the deck in the boat park and with the stack-pack cover itself in the garage.
Just finished making my own stackpac and bought 2x5mtr lenghts of aprox 75mm x6mm plastic strip from a plastic cladding supplier, then cut it down to suit. cost around £5