Printing 3 10x60 panos at 300dpi and all are printing extremely soft

[dgberg]

Thought I could figure this out but a first for me. 3-10x60 panos given to me at 300 ppi to be printed 3 wide on 36" Phototex.
The first batch of 3 was awful so we printed 1 up and it was perfect. We then printed two beside each other, both 10x60 and both were perfect.
We tried the 3-10x60's again and all were soft.
So what might be going on? The screen shot shows the screen resolution on the right and one of the bad prints on the left that was printed 3 up.
The good prints that we got printing either 1 or 2 up match the screen on the right perfectly.
Mac with Lightroom.
No change in any settings, 1 or 2 up I get perfect prints. 3 up all are soft.

[degrub]

just a WAG, limit on total dots sent in a file/job to the printer resulting in compression ?

[Christopher Sanderson]

Since LR/printer pipeline is cacking out on the resolution, my guess at a solution is to build an actual 3 x pano document in PS and print from that.

[dgberg]

Thanks both. First time for me and I have printed probably thousands of prints. I was aware of the Lightroom image size in pixel limitation but did not think I was even close to that.