If you have the option, you may try to open the file in Photoshop and export it from there.
My question is why Export to a .tiff file? For output? Re-check the print requirements. You might get away with a "Medium" resolution @ 150ppi. Has someone specifically asked for 300ppi image files?
36" x 300ppi = 10,800 pixels
48" x 300ppi = 14,400 pixels
10800 x 14400 = 155,520,000 pixels or 156 megapixels
Do you really need that kind of resolution
I print fine art on a 44" printers. Often to canvas or high quality paper. I can go as low as 200-240 dpi and not see a noticable loss in quality. But I am dealing with the future. I standardize at 300 dpi, so if I need to print 60" or 84" some day, my efforts creating these files can still be used.
In PS, I often work with files in the 2-3gb size accounting for layers. Harddrives are cheap, it is best to keep my work in a non flattened state. Just in case.
We shoot a 36.8 mega pixel camera that is 7,360 × 4,912. so a 10,000 pixel wide image is not that over the top.
I was able to EXPORT @ 300 dpi to a PS file (ART OPTIMIZED). But that file did some somewhat less of that white stroke?
I'd be happy to directly open my .ai file in PS, if it rendered it correctly.
After scouring Google for some answers I decided to figure out Illustrator's (frustrating) limits on my own. I may very well be using this program beyond its original design, but the high-end map data plugin I'm using (Avenza MAPublisher 9.4) apparently thought Illustrator was a worthy recipient of the high detail vector data that typically flows through it. (If you know of a program that can render .ai or .eps or any of AI's other vector formats at higher resolution, I'm all ears. It certainly isn't Photoshop.)
I am currently converting vectors of world maps from Natural Earth to fit NASA's huge Blue Marble map of the world at 86400x43200 for use in texturing a sphere in a 3D program with very up close views. (I hope this satisfies the "why would you ever render that large?" question) I was upset when I found out that Illustrator could not render this large, giving me a silly error stating:
"The operation cannot complete because there isn't enough memory (RAM) available"
and then would say:
"The art is too complex or too large to save as TIFF. Try saving with Anti-Aliasing not selected:
So I did a couple dozen renders and found the brink of possibility. Using a 216"x108" canvas, I was able to export at 214dpi in grayscale and 151dpi in RGB. Using a 216x216 canvas, I was able to export at 151dpi in grayscale and By process of elimination I discovered This doesn't appear to be a file size restriction because the resulting filesizes were 1.14GB and 1.68GB respectively. It also was not a RAM issue, as I have 32GB and never scratched the surface of that, whether rendering with AA or without. It was also not due to the complexity of the artwork, as the redner failed when I rendered 1 dpi higher whether I was rendering 400K vector lines or just one line. As far as I can tell, it's an arbitrary limit on the number of pixels that can render (that takes the number of channels into account, of course).
If you want to do the math yourself, the maximum pixels for color were
46230px x 23118px = 106874514px or 1.068Gpx
23112 x 23112px = 534164544px or 534Mpx
But if you'd rather let someone else do it I made a calculator for it here since I'll be using it a bit more to render things in chunks:
If you click on the intersections of the lines you can see your maximum possible resolution in x,y coordinates (aka width/height) and read the instructions to find the DPI you'll need to reach it.
This calculator is of course based on my experience with a very high end Mac Pro running Illustrator CC (running in 64 bit), Mountain Lion (64-bit) and 32GB of RAM on tap. For example the initial poster's art should have rendered according my calculations, (says he could have rendered at 554dpi in RGB with his 48x36" artboard)
300 ppi is far too much for posters as big as that. You could easily get away with half of that. Or even less.
Think about how closely the posters will be viewed from.
Will anyone ever poke his nose into the poster or see the difference between 300 ppi and, say, 150 ppi?
Steve Fairbairn made a good point. 300ppi is optimum for a distance from hand to eye. The further from the eye you go, the lower the ppi can be. I have heard of some billboards printed at 12ppi. It is so far away, so one can tell.
I'm working in fine art and need 300 dpi. I print on a 60" 12 color printer. The main issue is exporting to PSD will work but the render is not good. It shows white strokes where there are none in the file. The same export at TIFF does not show the strokes. But ILL will fail to render the same resolution as the PSD. I may have to figure how to export sections and then in PS tile them back. Roo bad Adobe can't fix this. a 2$" or 36" 300DPI Tiff is not that extraordinary.
Try doing a print test with just a part of the image. Try ( for example) 300 ppi, then 150 ppi, then 75 ppi and see if you can see the difference at normal viewing distance. Chances are that you won’t.
U can test version Ai CS6 & Ai CC which one can export.
Note: Test the same Hardware also.