Blur the middle layer

Select the middle layer (layer 1) by left clicking it, then select Filter...Blur...Gaussian Blur - 10 usually works pretty good.

If you only added a border to the second layer you may want to skip this step.

Blur the middle layer

Select the middle layer (layer 1) by left clicking it, then select Filter...Blur...Gaussian Blur - 10 usually works pretty good.

If you only added a border to the second layer you may want to skip this step.