Different sizes/dimensions on export & save as web in Illustrator CS5

Question

I have a file which is 1020px X 200px Artboard/Document dimensions and the drawings coves the whole artboard as follows.

When I "Export" the file as "png" (File>Export) it's dimensions change to 4250px X 458px as follows.

However when I use "Save for Web & Devices" (File>Save for Web & Devices" and save as "png" it's dimensions remain the same i.e., 1020px X 100px as follows.

Any idea why this is happening? Files are saved with similiar options viz. png-24 format, clip to artboard, save as background, interlaced, rgb color profile.

Answer 1

Tick the "Use Artboards" option when exporting if you want image to match artboard sizes. Otherwise, the image exports at it's given size, not the artboard size.

The vast difference in export sizes could be due to raster effects like the drop shadow.

Also, (based on comments below) a file exported at 300ppi will be much larger in terms of dimensions than a file exported at 72ppi. Since png files don't store data such as ppi, the file dimensions are adjusted to accomodate a higher resolution.

Answer 2

To match the same size of the artboard you must export it with a resolution of 72ppi. If you change it to 150ppi or 300ppi (or any other), the PNG will increase its size in order to fit that resolution

Answer 3

You were exporting at High (300dpi) resolution. On the other hand, "Save for Web" has an automatic resolution of 72dpi. The 300dpi PNG is larger than the 72dpi PNG because the number of pixels in the image has increased, while the print size has remained the same.

It's easy to Export an image to PNG with specific pixel dimensions if the target resolution is 72dpi. Simply set up the Artboard to exact pixel dimensions and Export with "Use Artboards" selected.

However, exporting an image in Adobe Illustrator to PNG format with specific pixel dimensions using the High (300 dpi) resolution setting, unfortunately seems to require math on a user's part and potential manual resizing of artwork. I haven't found any automated solution for this in Illustrator settings nor online.

Instructions:

1. Divide your final desired pixel width by 4.166 (Using the example from the question, 1020px / 4.166 = 244.839).

2. In Illustrator, set General Unit Preferences to "Pixels."

3. Create a blank Artboard at your final desired pixel dimensions (in this example, 1020px x 100px) or resize an existing Artboard to your final desired pixel dimensions.

4. Keeping proportions locked, change the Artboard width to the quotient in step 2, rounded up or down to a whole number, as appropriate. (In this example, the width would now be 245px and the height will have automatically changed in relation to the width to 24px).

5. Add art to Artboard or resize existing artwork to fit.

6. Export to PNG with "Use Artboards" specified, using High (300 dpi) resolution.

The result should be a PNG file of the image with 300dpi resolution and final desired pixel dimensions (in the example, 1020px x 100px).

By the way, "4.166" represents the amount of enlargement that occurs when a 72dpi image is converted to 300dpi. If you Export a file in Illustrator to PNG format with the Artboard set up to your final desired pixel dimensions, and with "Use Artboards" and High (300dpi) resolution specified, the dimensions of the resulting PNG file will be 4.166 times larger than your final desired dimensions.

Converted pixel width, at 300dpi / final desired pixel width, at 72dpi = 4.166 (Using example, 4250 / 1020 = 4.166)

I'd love to know if anyone knows of an automated way of doing this!

Answer 4

I have seen this problem in CS6 too. It seems that when the artboard coordinates (X and Y) are not perfectly positioned on a pixel coordinate causes a size change due to some rounding issue when using "Export" in the file menu.

I created a number of 184 x 184 px Icons using arboards (W:184 px H:184 px) and just alt-dragged them to create copies. Then I realized that the artboard coordinates didn't end up exactly on a pixel (eg. X:3617,21 px Y:-1787,83 px). This particular artboard ended up being 185 x 185 px when being exported.

So I adjusted the artboard postion X and Y to "exact" pixels (X:3617,0 px Y:-1788,0 px). After this I got an 184 x 184 px image when exporting.

Answer 5

The same thing happened to me in CS6, but I saw what I was doing wrong.

When I created a new document/ artboard for web, I use to change the measurement units to millimeters (because it was easier to put into perspective when designing) but when I didn't change the units and copied the mm image to the pixels image it was much larger.

Lesson - don't change the measurement units. When you create an artboard in pixels keep the unit measurements in pixels and then save it in 72ppi.

Answer 6

Click on your your artboard tool in Illustrator (shift+O) then use it to select an artboard. At the top of your screen should be four input boxes (X, Y, W, and H). These must be whole numbers, so if you have moved your artboards around they are probably sitting at random values like X=30.23 and Y=55.82. Just select the digits after the decimals and delete them.