Printing liquid transfer and supply system

A printing system for printing on a print media comprising:

• a first printhead for printing on the print media;
• a first liquid supply module including a first liquid reservoir in fluid communication with the first printhead, the first liquid supply module providing liquid from the first liquid reservoir to the first printhead;
• a second printhead for printing on the print media;
• a second liquid supply module including a second liquid reservoir in fluid communication with the second printhead, the second liquid supply module providing liquid from the second liquid reservoir to the second printhead;
• and
• a liquid transfer module that transfers liquid between the first liquid reservoir and the second liquid reservoir, wherein the a liquid transfer module includes a valve set that controls liquid flow from the first liquid reservoir to the second liquid reservoir and from the second liquid reservoir to the first liquid reservoir.

A method of transferring liquid in a printing system that prints liquid on a print media comprising:

• providing a first liquid supply module including a first liquid reservoir in fluid communication with a first printhead;
• providing liquid from the first liquid reservoir to the first printhead using the first liquid supply module;
• providing liquid from the first printhead back to the first liquid reservoir using the first liquid supply module;
• providing a second liquid supply module including a second liquid reservoir in fluid communication with a second printhead;
• providing liquid from the second liquid reservoir to the second printhead using the second liquid supply module;
• and
• transferring liquid between the first liquid reservoir and the second liquid reservoir using a liquid transfer module.