what is the proper "fill line" target for plastic jugs?

[GV2]

After 6 years of producing and gifting I am going to sell a few jugs to some co-workers. I always fill my "give-away" jugs to about a 1/4 inch from the cap. I don't want to "short" anyone who is willing to pay so I thought I would ask. Should I fill right to the cap? PS: I do not see a "fill line" marker on the empty jugs I purchase.

thanks

[psparr]

If it tastes good I don't think you'll have any complaints.

The only real way to know is by weight. Weigh it hot and see how high it comes up the neck. Once you have that, your good to go.

[SeanD]

Typically, the hot fill is to just below the threads/neck.

[maple flats]

If it's a maple container it is sized for hot fill to the bottom of the threads.

[GV2]

Thanks folks, looks like I have been doing it about right. I was also concerned about the seal factor. I read that the syrup shrinks a bit as it cools so I wanted to make sure I had that aspect covered too. thanks again.