Wide format Printing

Nalin,

This statement by John (jdanek) is still true:

"Talk to the print vendor and get their file requirements. They are the best person to tell you what file format to send them. Most grand format printers are used to scaling up a file."

Those requirements will include the PPI needed at the full size.

With the final resolution of 75 PPI also stated by John, that number (or the corresponding number given by the printer) should be multiplied by 12 and be 12 x 75 = 900 if you create the artwork in 1:12 with the same figures in " (inches) as the previous job, or similar.

You can also calculate the size in pixels x pixels for each image as 900 times the final size in ft.

The two ways of calculating ought to give the same results.

You are welcome, Nalin.

John mentioned 75 PPI needed for the final size, which corresponds to 900 PPI at 1:12 (far from the 3600 PPI). He makes the corresponding calculation and says 300 PPI at 1:4.

"But i scaled it up line is same."

You need to ticke Scale Strokes & Effects. You can do that in a number of places including the Transform palette (flyout). There may also be a few other scaling issues, depending on the actual artwork, as you can see here,

https://community.adobe.com/t5/illustrator/problem-resizing-rectangle-with-rounded-edge/td-p/10802112

Nalin,

In continuation of what John said, and also with future cases in mind:

When you create the artwork at a smaller scale and need to scale it up, there is no issue with artwork that is purely vector.

The issue is with anything raster, and this applies not only to raster images such as PNGs and JPEGs, but also raster effects such as Gaussian Blur and Drop Shadow (also known as Photoshop Effects).

The latter are easily overlooked. The resolution in PPI for those is set in the Effects>Documents Rater Effects Settings. See more below.

All things raster in the downscaled AI document must be created with a resolution that is so much higher that the final resolution becomes right.

So if you have vector artwork with raster effects, and/or raster images, to get the required PPI at the final size, you will have to increase the PPI in the Effect>Document Raster Effects Settings in the scaled document by the reverse scaling factor.

So if you create the work at 1:4 the raster effects/images PPI must be 4 times higher, if you work at 1:12 the raster effects/images PPI must be 12 times higher, and so on.

For raster images, you can also make sure in another and simpler way, namely by simply choosing an image size in pixels x pixels that gives you the right resolution in PPI/DPI at the final size, in other words the image size you would use if you created the whole thing at full scale. When scaled down in the AI document the resolution will just be increased correspondingly, no calcuilations needed.

In your present case, presuming it was created by someone else with the knowledge mentioned above, I would stick with the present 10" x 50" size and the scaling factor of 1:12 and just make sure the PPI is scaled up by a factor of 12, for the following two reasons (When I started writing all this I had three, but I forgotten the third one; it may come up later):

1) Whoever made the AI document has probably chosen that scale to be able to work with the exact same numbers (1.25" for 1.25' and so on), thereby avoiding possible errors owing to unnecessary calculations; it also makes it easier to check that all numbers are correct:

2) If you just scale up the present AI document by a factor of 3 from 1:12 to 1:4, the Effect>Document Raster Effects Settings will keep the same PPI, which is presumably 12 times higher than the final PPI, so when you scale up by the factor 4 their PPI will be 3 times higher than needed.

About raster effects: As stated here,

https://helpx.adobe.com/illustrator/using/effects.html

Raster effects are effects that generate pixels, rather than vector data. Raster effects include SVG Filters, all of the effects at the bottom section of the Effect menu, and the Drop Shadow, Inner Glow, Outer Glow, and Feather commands in the Effect > Stylize submenu.

It works on all the raster effects in the document, including those created before your changing the setting.

Instead of using 10" x 50", divide the file 10' x 50' by 4 ( 30" x 150" ).  Grand format resolution is 600dpi / 75ppi.  So, in your 30 x 150 inch file, Place images with resolution of 300ppi; set your raster resolution to High in Illustrator.  In the printer's RIP, they will enlarge your ( PDF ) 400%.  When they do, the image resolution will be 75ppi.  That may seem like a low number, but more than enough for grand format.  Obviously you should not send the vendor a TIFF file because of logistics, however you could.  Which leads me to my next recommendation.  Talk to the print vendor and get their file requirements.  They are the best person to tell you what file format to send them.  Most grand format printers are used to scaling up a file.

So you just started in your job as a digital printer? The documentation should tell you that. It most probably varies from machine to machine, so you might want to get that documentation and read it.