If you’re fairly new to fabric designing, especially using design software, you may still be struggling with seamless repeats.  This is one way of doing it, using Photoshop Elements:

1, Create a new blank file.  The size will depend on how big your design is, but make your canvas a bit bigger.  Make sure the resolution is 150dpi.

2. Start creating your design in the centre of the canvas.  When you’ve finished, merge the layers.

 

3. Select the left-hand part of the design.  Click on Layer, New, Layer via Cut.

4. Use the Move Tool to move the left-hand part of the design to the right-hand edge.  Use the arrows to do the moving so that the section doesn’t move up or down.

5. Move the right-hand part of the design (now on the left) to the left edge of your canvas, or until there is sufficient space between the two parts of the design.

6. Fill up the space with your design.

6. Repeat steps 3 to 5, horizontally - select the top of the design and move it to the bottom and so on.

7. Merge layers and flatten the image.

8.  If you have excess canvas at the edges of your design, then you will have to crop your image.  Be very careful to crop right to the edge of the design (or you will have white lines when your design is printed) but no further (or you may lose some of the image.)  It's worth taking your time over this and cropping one side at a time.

9. Save.