I think the manufacturers' point was that the caps sealed well enough 
for transport/delivery the first time and sealed well enough for in-home 
use thereafter, but that the milk bottler would not want to re-use 
them.  Hence the cheap supply of replacement caps for the manufacturer.  
By the time we got milk delivered, it was a dieing industry.  And it 
definitely had tabs on the cardboard seals for loose resealing at home, 
but you threw away the cardboard when it was empty and sent the bottle 
back without it.
Meli Diamanti

Carol Serr wrote:
> They call me Ms. Literal.  Sorry.
>
> So...home consumers of milk had a ready supply, at home, of these disks...to reseal their bottles?   I'm not quite old enough to have 'experienced' this closure type, but had heard my parents mention them.  My dad even claims he 'invented' (at least in his small town in SD) attaching a tab to make opening the lid much easier.  He showed the milkman his 'invention', and some months later (kid time)...bottles came with lids with a tab! I imagine many folks "invented" this means of opening the lids...to make it easier.
>
> Regardless (one part does mention they Can be reused tho)..the point being...the disks for sealing milk bottles were not made out of hard rubber.  Hence, I don't think Candace's disks were for such function.
>
> :o)
>