On Sunday, 8 September 2019 22:26:57 UTC+1, newshound wrote:
On 08/09/2019 19:33, tabbypurr wrote:

18mm won't go anywhere. 6mm should be alright but no guarantees long term, it's thin & can go out of whack. Hardboard of course has even worse rigidity - it isn't. ISTR one pelmet bing supported by the rail using clips that miss the curtain mechanism.


NT

They used to use hardboard with vertical "ripples" about an inch wide. I
guess that makes it a bit thicker and hence stiffer.

I'd quite forgotten that. Hideous stuff IIRC.


NT