Chalk line housing with cartridge tear mount

A chalk line reel comprising:

• a chalk line housing comprising:
• an interior space;
• a mount structure for releasably mounting a chalk cartridge;
• and
• a seal breaking structure configured to break a frangible sea of the chalk cartridge to allow chalk to be dispensed from the chalk cartridge into the interior space with the chalk cartridge engaged in the mount structure;
• a reel mounted to the housing for rotation relative to the housing about a reel axis;
• and
• a chalk line wound around the reel and engageable with chalk contained in the interior space.

A chalk cartridge for use with a chalk line reel, the chalk cartridge comprising:

• a cartridge housing comprising a chalk compartment at least partially filled with chalk and a chalk dispensing opening;
• mount receiving structure, defining a sliding axis, configured to slidably engage the chalk line reel, along the sliding axis, to releasably mount the chalk cartridge to the chalk line reel;
• and
• a frangible seal closing the chalk dispensing opening;
• wherein the frangible seal and the chalk dispensing opening form an acute angle relative to the sliding axis.