To freeze: Spoon into a rigid container and freeze for up to 3 months.

They should be kept in a rigid container made for the purpose and stored in a secure place.

Then mount over each vessel an inverted, rigid container full of water, such as a wide-mouth glass bottle.

A jar is a rigid, approximately cylindrical container with a wide mouth or opening.

This is the same so it tends to cancel when the rigid container is tared.

A bottle is a rigid container with a neck that is narrower than the body and a "mouth".

If possible carry sandwiches in a rigid container.

She tried to arch her whole body as a rigid container to preserve her fetus from shock.

"You need a rigid enough container for a snap-fit, and that won't happen with paper."

Just do not do it in a rigid container!