First,  my apologies;    in trying to sort out what appears to be a technological error I have perhaps made matters worse.

Contributor lowdifflocker wrote:

“Hi

“I need to replace my existing wooden sail battens, two of which are snapped.  The sizes are 2No, 750x36x5mm 1No, 590x36x5mm.

“I found a set on Trident, but they are only 15mm wide, does this matter?”

For some obscure reason this post was hidden,  although I received it by email.   When I tried to restore it from the bin it then disappeared entirely.    Sorry about that,  since this seems a genuine enquiry.

To answer the question,  The original battens are described as being wooden,  which was a popular batten material 50 or more years ago,  but very rarely found nowadays.   If you want to replace with wood you could try making your own,  or having them made,  and I would suggest in that case making them from ash.    (Or just possibly try repairing the broken ones,  by letting in a graving piece,  with scarf joints,  again using ash;   but making new would possibly be no more difficult,  and probably more satisfactory.)

Most modern battens are plastic of one form or another,  and significantly narrower.   My only concern about them would be the possibility of twist,  if inserted into a pocket wide enough for a wooden batten,  and therefore much wider than these modern battens are designed for.   One reasonable approach would be to try them and see what happens;   if they work properly,  well and good;   if they twist (and thus obviously distort the sail) ask a sailmaker to run a line of stitching along the pocket to reduce the width to that suitable for the modern battens.

Hope this helps,

Oliver