For print you can better use either psd or tif.
Jpg is lossy, meaning information is lost as pixels are averaged. If you shoot jpg, your camera already does this calculation a first time, so the file size is smaller. When you then open in PS or whatever, you get a full-size file becasue all pixels are shown, When you then save again as jpg, even when you set to maximum quality!!!,  the compression works again and your already averaged pixels are further averaged. For the web, seen the fact that you usually reduce the size, this is not a real problem. But for print you inevitably  move towards visual artefacts.

There are no Borg. All resistance is fertile.