Amber with measuring line?

[Yooper14]

Hi all. first time on the forum.
I'm working a turn of the century - 1950's dump and getting some valuable milk bottles. Just scratched up this interesting amber that I'm not too sure about. It has a measuring line embedded in a concave rectangle. Above and below the line are arrows pointing at the line and "1/2" written at both ends.

The only info I can find is that these are used for mixing oil or dressings for cooking? Is this the right track?

Thanks for your help

Yooper

 

[whiskeyman]

this is a CERTO bottle...had something to do with home preserving...canning,etc...Also occurs in 7up green....

 

[chrisboyles]

I also have one of these except mine says certo and has a line that says fill to here for half of cup. Are they common>?

 

[preditor]

I have one also , it says certo but i didn't have a clue what it was
Preditor[8D]

 

[whiskeyman]

The amber is common...I have seen only a few of the green. Both are valued under $5.00

 

[Yooper14]

Fantastic, everyone! Very quick and courteous replies. I'm sold on this site!!

 

[DiggerBryan]

So, that is what those bottles were. I'm not kidding you I have dug up 35-40 of these bottles in just ONE of the dumps I am digging. I haven't kept any of them, just put them back into the ground. I actually started throwing them over a hill at one point. []

 

[Yooper14]

Here's an ad I just found for Certo. Interesting...you can see the bottle at the bottom...must've had a label on the smooth edge?

 

[whiskeyman]

YOOPER...WTG on finding the ad so quickly !!

I keep a few Certos...like the green...and also have a couple in yellow amber...They'll maybe become like other bottles thrown back in the early days of the Hobby: Collectible , and then we'll be re-digging our old dumpsites to recover them...LOL.
(of course I'll probably be permanently in the ground by then).

 

[woody]

Certo is a fruit pectin.
It helps to make jelly/jam solidify when you make it. Otherwise, it would run like water.