Mason jars are a "no". According to staff, they don't have the ability to tare them beforehand, so unless you want to pay for the weight of the jar, you have to use plastic bags. Reusing Winco plastic bags would probably be kosher, and of course you can always bring your reusable bags to bag your groceries.
No, because all bulk product is weighed for pricing. The containers'/bags' weight is already known which is why they are provided for free when purchasing bulk.
I have know idea, calm and ask them!!!
I made some bags out of pillowcases. They had no problem with that. I'm sure the only issue with jars would be the weight of the jar.
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