Offset Tool
Combined with the Clone Tool, the Offset Tool helps you to manually get rid of obvious transition lines between tiles.
One of the most complex parts of tiling is getting rid of the transitions between repetitions. At SEDDI, we always recommend using SEDDI Textura's Tiling Assistant as your first option, but there may be some cases where a more human touch is beneficial.
An example where Offset Tool comes in handy, is not having enough scanned space around the repeat area to for Tiling Assistant to work. In cases like this, the best approach is to use the Offset Tool with the Clone Tool.
Before getting started, take into account that Offset Tool:
Needs the minimum repeat to be cropped to work best.
Needs the minimum repeat to be aligned to work best.
Needs to be used before the Clone Tool.
Modifies the selected area, but does not modify the aspect of the fabric.
Knowing this will help you improve your results.
Example
A piece of fabric where the minimum repeat has been selected, and then it has been aligned.
Once the image is ready, click on the Offset Tiling Tool icon 
In this case, we can see that the transition is obvious. Also, because the transition is on the edge of the image, it can't be resolved with the Clone Tool alone. For this reason, we need to shuffle around the image to bring the edges to the center of the repeat.
This how the Offset Tool works: It repeats your image four times and then offsets the selected area to the center of those images.
This results in an image that is slightly different from the original selection, but still generates the same repeat.
As you can see in the example below, the result is now an image that has the obvious edges in the center of the image. This will allow us to easily use the clone tools to remove this partition.
The left image shows how the selection has a clear partition in the center horizontal and vertical axis. The image on the right also shows how now, the partition is in the center of the tile—but the transition to the other tiles is seamless.
If we need the image to remain with exactly the same selection as we had in the beginning, we can use the Offset Tool again after we use the Clone Tool, and the image will go back to its original selection, but with seamless edges.