Achieving a Stripe Effect?

[Chick]

Setting the dpi higher will not do anything. The only time you'll see a difference by adjusting that resolution is when you print. (Okay, almost the only time. Some programs have an "actual size" button, but its usefulness is dubious unless the program also knows the physical dimensions of your screen.)

Ascension's got it. However, turning a 1 pixel line on an angle probably won't work out so well because the anti-aliasing will just turn it into a hazy blur.

Let's think about this. If you have an image that is 1 inch by 1 inch and you have a resolution of 10px/inch, then one px is 1/10 of an inch. That means the smallest line you can draw is 1/10 inch thick. If you have that same image that is 1 inch by 1 inch and you have a resolution of 1000px/inch, then one px is 1/1000 of an inch, and the smallest line you can draw is 1/1000 of an inch thick. So resolution does matter in how fine a line you can draw. Remember, dpi and resolution are not the same thing. dpi only matters in printing. Resolution matters on the screen. They are connected, but not the same. Or do I have this all wrong?

[Midgardsormr]

Inches do not exist until you print. If you have a 1600x1200 px image at 72dpi and you increase it to 600dpi, you still have only 1600x1200 pixels. You haven't changed the image, only its metadata.

If you have the resample switch turned on in Photoshop, though, then changing the print resolution will change the pixel dimensions as well.

The whole 72dpi for screen thing is one of the more difficult to dispel myths out there.

[Gamerprinter]

Inches do not exist until you print. If you have a 1600x1200 px image at 72dpi and you increase it to 600dpi, you still have only 1600x1200 pixels. You haven't changed the image, only its metadata.

This is only true with image editors like Photoshop/GIMP, if using a vector application like Illustrator or Xara, you have inches at the start, and no such thing as a pixel until you export to bitmap format. So it depends on what application you are using - it differs between applications.

[Midgardsormr]

Very good point. Although there are still pixels because the image needs to be rasterized for the screen. I can be pedantic, too. ;-)

In either case, changing the dpi will have no effect on the image until it comes time to print. Change it to 32 or 32000, and your image will be unchanged.