Affinity Photo : How To Slice Text Tutorial | Graphicxtras
Convert to curves (or regular paths)
The first thing to do before slicing the text is to convert the text to standard curves, it does mean that the art is no longer editable if you want to change the lettering. Before you do this, make certain it is correct, run a spell checker
Adding slicing rectangles to your text in a group
Once you have the curves, you can now add the elements to slice the curves with. If you go to the layers panel you will notice that the characters are now in a group. You will need to add the items to the artwork inside that group. Select the first letter 'curve' in the layers panel group and then add a rectangle (you will need to add multiple). I would suggest adding it in a different color to the words, such as in red if the letters are in black.
Add multiple rectangles
You can then duplicate the rectangle shape repeatedly by using the alt / option key and dragging with the move tool selected. You can re-size the rectangle etc, perhaps make it thicker.
Select entries in the group
Go to the group now with the rectangle and converted curves and select all the entries in that group (you can not select it at the group level, it does need to be selected at rectangle / curves level).
Apply geometry / divide command
To cut the letters, go to the layer menu and geometry and divide. The divide feature splits the letters as well as the rectangles so you will end up with paths created where there is an intersection of the stroke. Divide doesn't worry about the arrangement of the curves etc
Select the red shapes leaving only the letters
You will notice very little difference. The difference is in the layers panel where you will now see probably loads of new lines. If you have used the approach of red lines and black type, you can select the red lines very quickly in the layers panel. Sadly there is no equivalent feature to the select all shapes that are the same color etc. Delete the selected curves in the layers panel.
Repeat process if you wish perhaps diagonally
You can continue to divide the type by adding additional rectangles such as horizontally or diagonally or perhaps using different sized chunks etc as long as they are added to the same group.
Again, select all the curves and paths you want to use (not the group) and then go to the layer menu and geometry and divide and then remove the additional red lines and curves
Pen tool and jagged divide
The same approach can also be used with just a basic line and converted characters. The line can be created using the pen tool and it can be applied across the design. It does not work in exactly the same way. If you create multiple straight lines just with a stroke and then use the divide as above then it will fail. If you use the pen tool and add lots of lines across the design then on using the divide you will notice that the lines have become a closed path and you will end up with a very patchwork set of broken designs but it is still an interesting way of creating an odd design. Apply the layer menu and geometry and divide to create the broken artwork. You will end up with the cuts but the type is harder to see but it still can be broken apart and manipulated
Re-color the curved designs
You can always re-color each of the fragments. Select each fragment and then go to the swatches panel and select a color. If you want you word to stand out then you can fill the word with lots of different colors. If you want the surrounding area to be colorful, select those fragments and fill with color and leave the type white or a solid color. Generates an interesting design. https://youtu.be/y7wwmMn_2eg