Yesterday I did this post >>61854612
But today I tested again with the same printer but on ubuntu mate 17.10. and this time instead of gutenprint i used epson's driver.
I got much better results. still not the same as windows but i can't complain on that since neither windows nor linux is making use of color management.
And I found tutorials on how to do this on linux. So i'm confident i'll get even better print quality in both operating systems
so next time you want to print on linux just remember to use an updated distro, make sure your printer's driver is installed, and perhaps avoid gutenprint
I forgot to mention.
Left is Linux. Windows is Right
And like before both prints were done using gimp 2.8