You are so happy that you’ve found the perfect image for your project. it is not big enough so you decide to repeat the same image into your canvas, then you realize that this image has some really visible seams. Do not worry, we got you (and Photoshop also).

Step 1: Import your texture into Photoshop.

Step 2: Photoshop has this amazing option called Offset, it shows you what the image would look like if it was wrapped around, meaning how will the left side look next to the right side. We are going to look how our texture would look. Go to Filter > Other > Offset.

Step 3: Once the window pops out, you will be able to adjust it either horizontally or vertically. You will start seeing the edges and what you will need to fix. Click OK.

Step 4: In these visible seams, we will be using the clone stamp tool.

Step 5: You can also use other correction tools to adjust for example the lighting. In this case we use the Dodge and Burn tool.

Step 6: Run the Offset tool again to see how the corrections are going. You can adjust the pixels to look out for any other visible seams.

Step 7: Create a new test document to put in your seamless texture to really see how it will look when ready to use.

Step 8: In your new document, you will see how the texture will tile. As you can see here there are still some visible seams. This will help you out to see exactly where the correction needs to be made.

Step 9: You can also use other methods to correct your image. Using a adjustment layer > Curves, will help you see where the brightness needs to be corrected.
Now, you may have a more complex image that you want to fix, make sure you use the clone stamp tool, the dodge and burn tool to correct its lighting. You can also use the camera raw filter to adjust the lighting. until you’ve acheived your final result.