Don't use the invisible frame. Import the .ai file to Photoshop rather than the eps. As long as you save it with "pdf compatible" checked, you will then have some "crop to" options when you import it into Photoshop. Select "Crop box" and then flatten your image.

so it seems only ai file will make photoshop raster around the artboard? will it be a problem that eps raster size is not same as jpg preview? I mean seem photoshop doesn't recognize the artboard in eps, so if buyer or the site system generate a jpg if will be fit to the vector instead of artboard.

It doesn't matter what the .ai or .eps size is as long as the final eps file size isn't too big (that's a different topic altogether). For the jpeg preview I normally make it quite large in case someone just needs the bitmap version and not the vector. I'm referring my work flow to IS. It may be different on other sites. Also, there are many ways to skin a cat, so just consider this one way

Finally i found someone do the same thing as me.

I didn't have problem with istock, but just recently got a rejection because of the no fill and no stroke frame.

It seems some system will generate thumbnail from the eps, so without the frame, i think the jpg preview will fit to the vector instead of artboard.

here are the istock rejections:

Please remove the white shape from behind your illustration. Adding backgrounds limits a client's ability to place the illustration onto different colored backgrounds.

In addition, please note we do not accept files with unfilled/unstroked objects in backgrounds as they cause clients problems when editing and/or importing files into different programs.Please crop your preview more closely to the subject. The composition of your preview contains an unnecessary addition of blank/negative space.

I recently adopted this technique of an invisible frame around the artboard (not transparent but with no fill and no stroke). Mostly for the sites that generate the jpeg on the server side. For now, I had no rejection by Istock for that reason.

Quote from: mtkang on April 22, 2012, 00:28

saying the invisible frame can be a problem to some applications.

Would be nice to have confirmation of this.

I recently adopted this technique of an invisible frame around the artboard (not transparent but with no fill and no stroke). Mostly for the sites that generate the jpeg on the server side. For now, I had no rejection by Istock for that reason.

Quote from: mtkang on April 22, 2012, 00:28

saying the invisible frame can be a problem to some applications.

Would be nice to have confirmation of this.

I hate sites that generate the jpegs server side. I make my vectors with really small native resolutions to keep the file size down when using transparency screens. When they generate the jpegs they usually do it by just opening the eps in Photoshop rather than resizing in illustrator then opening in Photoshop or exporting so you get a horribly pixellated jpeg. Yuk

ETA more on topic, I just add the white space to the jpeg by increasing the canvas size in Photoshop (I upsize the eps in illustrator then save as AI then open it with Photoshop to create the jpeg)

I use Illustrator. When I make my jpeg for iStock submission I export my file.  If you do this there is an option at the bottom left of the dialog box that you can check and then Illustrator will use your Artboard instead of fitting the vector. Hope this is useful.

This sound interesting, I'll have to check it out.

If you use transparency blends the native resolution in AI will determine how these effects are rasterized when creating the jpeg.
When I was saving to eps8 up-sizing was unnecessary (but then again file sizes were smaller in any case)

Try an experiment by downsizing a vector that uses transparency blends overlaid over other objects and resize it to be really tiny, then create the jpeg from that and see how bad it looks.
I save my eps files with really small dimensions, because if I make them any bigger the file size skyrockets. I think it's because I often overlay large areas of the image to get the effects I want, sometimes with several different objects with different blend modes.

I found out the hard way, when I zoomed in on some of my images on Canstock and found the previews were horribly pixellated. The sites that still generate the jpeg versions this way need to rethink things now that eps10 files are becoming the norm. It's no longer as easy as always just opening the file in Photoshop at any resolution you want and it being okay.
As standard I would say sites now need to ask for a large jpeg to be uploaded with the vector file, then give the large jpeg with any vector purchase as well as using it to generate the different size raters for separate download.