How full to fill it

Fill to the declared weight and a jar of leaf will look underfilled. That gap has a regulatory name and a defense, and it is worth knowing both before a customer raises it.

Fill to weight and accept the space

The declaration is a net weight, so the weight is what must be right. Whatever volume that weight occupies is what it occupies, and for low bulk density material it will not reach the shoulder.

Topping up to look better means overfilling, which costs you product on every unit and does not change the declaration.

Slack-fill is a legal term

Slack-fill is the difference between a container's actual capacity and the volume of product in it. Where a container does not let the consumer fully view the contents, fill that contains nonfunctional slack-fill is considered misleading.

Note the condition. A clear jar where the customer can see exactly what they are getting sits differently from an opaque tin. That is one more argument for clear glass on the materials where fading is not the dominant risk.

What counts as functional

The regulation explicitly allows slack-fill that results from unavoidable product settling, and from an inability to increase fill or further reduce package size. Both apply squarely to spice: powder settles in transit, and container sizes come in the steps a supplier offers rather than continuously.

So the defense is that the headspace performs a function or is unavoidable, not that the weight was correct. Those are different arguments and only one of them is the regulation's.

Reducing it honestly

Choose a jar sized to the material rather than to the range. Settle a sample overnight before committing, because the settled volume is the one the customer sees. And where a line genuinely cannot fill a jar respectably, the answer is a smaller jar rather than a larger claim.

References