Can't print with .am1x file on Canon PRO-300

[mrswitters]

I have a Canon PRO-300. I would like to use an .am1x file to make a print with Canson Fiber Platine Rag paper. I've downloaded the .a1mx file and installed it using the Media Configuration Tool. It appears when I click on "Custom" in the sidebar of the MCT, so it does seem that it is installed correctly:

However, I do not see this as an option listed in the Paper Settings menu on the PRO-300 itself. (Note: I'm following the instructions on this page of Red River's website. Although the paper I'm using isn't a Red River paper, these were the clearest instructions for using an .a1mx file I could find.)

When I tap on Paper Type, I do not see "Custom" as an option, and thus I cannot choose the Canson Fiber Platine file I sent to the printer. (On the Red River tutorial page, "Custom" appears below "Card Stock." On my PRO-300, Card Stock is the last menu option; if I use the down arrow to go below that, it resets to the top of the menu.)

What am I doing wrong? 

[mrswitters]

Also, there is no "Custom" option in the "Media Type" dialog within the Mac printer driver when I attempt to print. This makes me think the .a1mx file isn't correctly installed on the PRO-300. But if it isn't, why does it appear in the "Custom" menu in the Media Configuration Tool? 

[EduardoAlemao · Accepted solution]

Go to System Settings > Printers > [your Printer] > Options and Supplies > Utility > Open Printer Utility > Media Information > Update the media information of the printer driver.

So long! This should update your printer with the new paper 😄 

[mrswitters]

Thanks, that solved the problem!

[rcoda]

None of this works for me... Mac Studio, Sonoma, brand new imageGRAFPRO 310. Got the am1x file from Hanhehuehle. Can't find a way to get it to the printer. Tried making a new custom paper in the Media Configurator app or whatever. It generates a new am1x file. But it still doesn't make it to the printer (can't see it in the Prof Print app from Canon). This is driving me insane... who comes up with these ridiculous install procedures? This should be EASY! And I gave up drinking for Lent... I don't know if I can make it with all this crap! 😉