If you haven't already done so, you will probably want to read What is a CryptoPic? before you read this tutorial.

We're going to solve a 9 x 9 puzzle step by step. (It's included with the software as 'Tutorial'.)

This is what the pattern of clues looks like for our puzzle - so let's waste no time and set about solving it. The first thing to remember is: don't guess! You'll end up in a muddle. Instead, let's find things that we know for certain and build from there.

First, look for any clues which take up a whole row or column - here we have a 9 in the down clues, and the grid is only nine squares high, so they must all be black. Similarly, any rows or columns with no clues at all will have no black squares, so they can be marked with dots to show that they're white. It's a good idea to mark completed clues so you know what you've done - here the 9 clue has been clicked on to turn it grey.

Although it's less obvious, the "4 4" clue also takes up a whole column, because we have 4+4=8 black squares, and there must be at least one white square between them.

Now look at the 7 next to it. A group of seven black squares won't fill the column so we don't know where it goes, but there only three different possibilities, as shown on the right. Whichever one is correct, the middle five squares are black, so we can fill them in.

All the squares we've filled with black or dots will help us with the across clues too, so let's look at those. The 3 in the middle can be solved: there must be three black squares together but they can't go any further to the right because of the dotted square, so there's only one place the remaining square could be. There are no other clues on this line, so we can put dots in the rest of the squares.

Next the 4s on the rows above and below the 3. We already have three of the four black squares on each line, so there's only one more black square per row - either to the left or the right of the three we have. Again, we don't know which it is, but we do know that all the other squares on those rows are white. On the "4 1" row, however, we can't put dots in any of the squares yet, as any square to the right of the four could be the 1, and hence black.

Going back to the down clues, for each of the "2 2" columns, the second 2 must be the bottom two squares, so we can turn them black. What's more two of the three unknown squares at the top of the column are black - the first and second or the second and third - whichever they are the second square down is black. Likewise in the "2 1" column, the 2 is above the 1 so it must fit somewhere in the top three squares, too.

Looking at the across clues again, the 7s and the 5 at the bottom all have two clusters of black squares but only one clue per row, so the squares in between must be black, to connect the clusters. The bottom row is now complete, so we can put dots in the remaining squares.

Back to the down clues, the bottom 3 of the "3 3" column touches the edge of the grid, so it can only be completed by going upwards. The square above it must also be white.

Now, the bottom two "4" rows. One already has its four black squares; the other needs one more and has only one place to put it.

The 3 down must go one square further up, which completes the 4 across, too, and means that we've also fixed the positions of the 7s across.

The 7 down is complete so let's dot the final square above it - and now we know that the 5 across continues three more squares to the right.

Looking at the remaining down clues (left to right), we have two black squares where we need three so we add a black square, then we have two where we need two so we add a dot, then the same again, and finally we have one black square where we need two so we add another black square, and we've finished! As you can see, this CryptoPic is a picture of the moon - or a very bendy banana.

Hopefully the above tutorial has shown you some of the tricks and methods available for solving CryptoPics. There is, however, no fixed way of getting to the solution - provided you get to the right answer in the end, you can do it in any order and using any method you like.

As you get used to solving them, you'll discover your own tricks to make the task easier - for the most difficult puzzles, you'll probably need some pretty cunning tricks!

If you're ready to start solving, you can download the World of CryptoPics software or print some puzzles to fill in by hand!