InkDock D2C Printer - answer to Killer Sudoku puzzle
The InkDock™ D2C Printer from iTools is/was being demonstrated on the TOSHIBA TEC & IACS booth (540) at InPrint, Munich 2019. This direct-to-cylinder printer is/was printing a design onto cardboard tubes using the TOSHIBA TEC 600dpi CF3 printhead. Besides the above fish, there's also a "Killer Sudoku" puzzle included in the design. Both the unsolved and solved versions of that puzzle are illustrated below, including the rules for Killer Sudoku puzzles.
The objective is to fill the grid with numbers from 1 to 9 according to the following rules:
Each row, column, and nonet (block of 9 cells enclosed by thick lines) contains each number exactly once.
The sum of all numbers in a cage (group of cells having blue, green, pink or yellow fill colour in this case) must match the small number printed in its corner.