Lines can't connect with each other to make a rapport

[foton]

Hi,

At first I would like to introduce myself, my name is Foton, I have a photography studio, then work a lot with photoshop, but sometimes I find a stone on my way like that:

I need to connect a rapport with others(print on fabric for textile industry). It looks like a mosaic, however the pieces doesn't connect side by side at the same height, but side by side sometimes higher, sometimes lower.
The thing is: when I try put then together the limit of the layers create an edge that prevents connection.
I'm sending some images to try to make this clear: 1- all layers together with the thin line between the 2- closer to junction 3- closer 3200% to see what really happens.

Thank you!!

Foton.

 

[Remote-Medic]

Once you created these images, did you resize them in anyway?

 

[chrisix]

did you try selecting one, and then zooming all the way in, and then pressing an arow key to make them move one pixel closer, instead of dragging them with your mouse?