I know these as Hanjie, but I've also heard them called Paint by Numbers and Paint by Sudoku. They're a Japanese logic puzzle, in which you use number clues to shade in squares on a grid, until you end up with a picture in the end.

I am absolutely addicted to them, so in the spirit of sharing, I've created some new ones with a Professionals theme. If you haven't tried these before, read on for a tutorial.

Right. Here you have a blank grid. Notice the numbers on the side and the top? Each represents a solid line of shaded squares.

The sets of shaded squares cannot touch each other, and the numbers are read from left to right in rows or top to bottom in columns. So, if it says 2, 2, 3, that means the row will be filled in with two shaded squares, followed by one or more blank spaces, another two shaded squares, more blank spaces, and finally three shaded squares.

Two of the rows have no numbers at all. That tells you that none of the squares are shaded, so put a dot or a line in each one. This way you'll remember not to shade them in.

Some of the rows have numbers that equal the length of the row. You can shade those in right away.

And finally, the rest can be filled in using simple logic. For instance, if the top row across is 3, 2, 3, then you know there's only one way those three sets of shaded squares can fit together and still not touch. The second row from the top is a little trickier, but since you already know the first number is 2, then you know the third square can't be shaded. The final three squares in the second row can be filled in two ways, so you'd leave them blank for the moment, until you've solved the rest.

Now if you're ready to try some Hanjie on your own, or if you are already familiar with how the game is played, I have a variety of puzzles in PDF form for you to print out on my "Unclassifiable" page.