Text in Gimp

[Ofnuts]

Some ideas:

1. Compute the total length you will need
   
2. Create  an image where this length is a dimension, and the strip with is the other dimension.
   
3. Apply a gradient over it
   
4. Make sure it has an alpha channel (Layer ➤ Transparency ➤ Add alpha channel)
   
5. Cut/paste rectangles from it to you target image, rotating/adjusting each
   
6. Make a diamond selection (square rotated by 45%) about as big as your final image, invert it, and save it to a channel (Select > Save to channel)
   
7. Set the Move too to "Move Selection
   
8. For each layer, recreate a selection from the saved channel, and use it as  cookie cutter to clip the corners
   
9. Apply Filters ➤ Light and shadow ➤ Drop shadow to each layer, you want a bit more Y shift that X shift. Do it right on the first layer, and then select each layer in turn and then Filters ➤ Repeat "Drop shadow".