Apparatus, method and article of manufacture for producing an edible multi-color ink-image

A system for ink-jet printing, the system comprising:

• a. an ink-jet printer defining a target-location;
• b. first and second reservoirs of fluids respectively loaded with first and second fluids, wherein:
• i. the first fluid is an acidic, edible and aqueous ink comprising an extract of plant matter or solids of the extract of the plant matter, a color of both (A) the plant matter or the extract thereof or the solids of the extract thereof and (B) the aqueous ink being pH dependent;
• ii. the second fluid is an edible pH-adjusting liquid which is clear, or whose primary colorant is riboflavin or riboflavin-phosphate;
• and
• c. control circuitry for controlling deposition of droplets to print a multi-color edible in image onto a substrate disposed at the target-location by ink-jetting thereon droplets of both the first and second fluids, wherein the ink-ejetting of the droplets of the first and second fluids is controlled in accordance with a combination of:
• (i) a pH-color dependency of the first fluid;
• and (ii) a pH:
• mixing-ratio dependency of pH upon a mixing ratio between the first and second fluids.

An article of manufacture comprising:

• a. an edible substrate;
• b. a pH-heterogeneous edible ink-image disposed on an upper surface of the edible substrate, the ink-image comprising a first and second set of ink-dots, wherein:
• i. for each given ink-dot of both the first and second sets of ink-dots, a primary colorant thereof is an extract of plant matter or solids of the extract of the plant matter, wherein a color of the extract of plant matter or solids of the extract of the plant matter is pH sensitive;
• ii. for each given ink-dot of the first sets of ink-dots, a pH thereof is within 0.5 or within 1 or within 1.5 of a common first pH value and a color thereof is a first dot-color;
• iii. for each given ink-dot of the second sets of ink-dots, a pH thereof is within 0.5 or within 1 or within 1.5 of a common second pH value and a color thereof is a second dot-color;
• iv. an absolute value of a difference between the first and second pH values is at least 1.5 or at least 2 or at least 2.5 or at least 3 or at least 4;
• and
• v. at least one of a first dot-color-condition, a second dot-color-condition, a third dot-color-condition, and a fourth dot-color-condition is true, the dot-color conditions being defined as follows:
• A. according to the first dot-color-condition, the first dot-color is red and the second dot-color is selected from the group consisting of blue-violet, blue, blue-green and green;
• B. according to the second dot-color-condition, the first dot-color is red and the second dot-color is selected from the group consisting of blue, blue-green and green;
• C. according to the third dot-color-condition, the first dot-color is red-violet or violet and the second dot-color is selected from the group consisting blue, blue-green and green;
• and
• D. according to the fourth dot-color-condition, the first dot-color is red-violet or violet and the second dot-color is selected from the group consisting blue, and green.