Print substance gauge authentication

A print particle apparatus, comprising:

• a print particle reservoir of an imaging device;
• a mating interface coupled to the print particle reservoir to receive a print particle container;
• a locking mechanism coupled to the mating interface to control access to the print particle reservoir;
• and
• an authentication mechanism coupled to the locking mechanism comprising instructions to:
• determine properties of the print particle container when the print particle container is received by the mating interface, wherein the properties of the print particle container include a quantity of print particles;
• unlock the locking mechanism when the properties of the print particle container are within a receivable threshold of the print particle reservoir;
• and
• lock the locking mechanism when the properties of the print particle container exceed the receivable threshold of the print particle reservoir.

A system, comprising:

• a housing of an imaging device;
• a print particle reservoir positioned within an interior of housing of the imaging device;
• a mating interface coupled to an exterior of the housing to receive a print particle container to deposit print particles into the print particle reservoir when the mating interface is in an unlocked position;
• an authentication mechanism coupled to a locking mechanism coupled to the mating interface to allow the mating interface to move from a locked position to the unlocked position, wherein the authentication mechanism includes instructions to:
• determine a quantity of print particles the print particle reservoir is capable of receiving from the print particle container;
• determine a quantity of print particles stored in the print particle container;
• unlock the locking mechanism to allow the mating interface to move from the locked position to the unlocked position when the quantity of print particles stored in the print particle container is less than the quantity of print particles the print particle reservoir is capable of receiving.