why printing quality from illustrator is low

[mashzj@adobeforums.com]

use illustrator to open a tiff file(300dpi), the picture looks fine on screen. But the printing quality is bad and i could see pixel spots on the white background. My printer support 600 dpi, but the printing output looks like 40 to 50 dpi.The same picture could be printed perfectly well with other software like powerpoint.I need to use illustrator to generate EPS file, however the EPS file generated still resulted in bad printing quality. Can anybody please tell me how to resolve this problem.

[BobHill@adobeforums.com]

Mashzj,

Are you confusing print dpi (dots per inch), which is dependent upon what paper you are printing on (not the resolution of the image) or your impage ppi (pixels per inch) of the image to send to the printer. They are NOT the same thing, nor do they relate to each other except each can cause a good or bad print for different reasons.

If you are printing from other than Illustrator to a non postscript printer, that's why you are seeing your image in poor resolution. EPS is a print only to postscript format (unless your program has the ability to convert) and you are seeing and printing EPS as a TIFF header image in low res. If you wish to print, print from Illustrator, or if using EPS, print only to a postscript printer.

Bob

[mashzj@adobeforums.com]

Bob,
Thank you.
I still don't get it why the TIFF picture with 300ppi can not be printed in good quality from illustrator. I think printing a TIFF picture needs not to use a postscript printer. Meantime, my printer can print PS file with other photo editors with right dpi. I believe something else is not right.

[Jacob_Bugge@adobeforums.com]

mashzj,

To be sure of the actual image size and ppi you may:

1) Select the image,
2) Choose Window>Document Info which should pop up,
3) Tick right arrow,
4a) If Selection only is ticked, go to 4b), else tick it and tick right arrow again and go to 4b),
4b) Tick Embedded Images
5) Scroll to the bottom of the Document Info box.

[mashzj@adobeforums.com]

Jacob

Thank you for the advice.
I checked that the embeded image shows that the resolution is 300.375 by 299.751. But somehow, from the printed output I can even read the gray color spots(if they are so called pixels), of which the density is about 40-50 dots/inch. Is there way to eleminate those spots?

[BobHill@adobeforums.com]

Mashzj,

That's because you are not printing just any old TIFF, you are printing a low res TIFF that is placed onto the EPS file as a header image for such things. If you wish a true TIFF at 300ppi, then use a TIFF image without Saving it to EPS. It's the EPS format that does that for printing to OTHER than postscript printers. If you print to a postscript printer you will get excellent vector AND raster images that were originally placed into Illustrator at 300ppi. Remember that EPS is not printable to other than postscript printers. Other printers use the header image (if there is one). They don't recognize EPS as a printable language.

Bob