File size doesn't decrease

[Lee Hermans]

Hi,

I worked on a large file that was over 3.5GB (I could only save it in the end as a Large Document Format).

But now I have to resize it to a smaller JPG file with 180 DPI and the max. filesize can be 150MB. The fabric printing company requires these settings. But when I go to "save as... " I only have the options of Tiff, PNG, Large Document Format and Photoshop Raw. 

So I tried to decrease the file size by merging and flattening layers. But the file size stays the same (3.5GB). 

I don't want the loose the quality of my image since it has to be printed on a large format 260 cm x 960 cm.

I have added a screenshot of my "Image size" information.

Can someone advise me?

Thank you!!!

[Test Screen Name]

Your request is impossible. This is not a limit of Photoshop. It is a limitation of JPEG. You cannot do this, and nor can any other customer of your printing company do this.

You want 960 cm / 9600 mm / 377.95 inches. You want 180 ppi.

It is easy to see that this will be 377.95 x 180 pixels = 68031 pixels

But the design of JPEG is for a maximum of  65535 pixels.

So something MUST change for you 

- you can use less than 960cm

- you can use less than 180ppi

- you can save as a different format, not JPEG

You should not guess or experient, you need to ask your printing company what they expect you to do in this case.