Round It allows creating round corners for generated gradient images. It does work for all types of gradient except for the line gradient because the image height/width (depends on gradient vertical/horizontal orientation) for line gradient is always 1px.
Round It could comes handy when you need to create buttons, tabs and other small to medium size widgets (text over is not supported at this time - use HTML text over image).
Oval rectangle type gradient does not require enabling Round It and generates round corners by default. Other types of gradients do require checking the box next to Round It before round corner applied.
Each one of four corners could be selected to become rounded. That means you may create tabs where only top-left and top-right corners become rounded. By default all 4 corners are selected. If you need to deselect a corner use corner selector
Select Radius by typing the number directly in the text box. Generally the radius value should not be over half of the smaller side of the image. If you have a square image - 40x40px for instance, then the reasonable radius value should be between 2-20. Note: 20 would create a perfect circle for this image (point where round corners are joined together).
It is interesting to actually specify values over half image side size value - image would collapse and would look like a kaleidoscope effect with every pixel added to the radius value. Some of the images created that way could be used as a background pattern.
Use Backgrd to set the background color outside of the round corners. Generally this color should match the color of the background where the image would be used. You may leave it transparent but be aware - IE versions earlier than 7.0 do not support .png transparency.
With Round It checked or when you select Oval Rectangle gradient type the image is always generated with Anti-Aliasing - ON, regardless of actual Anti-Aliasing control setting (located below color selector).
Creating Line Gradient Images with round corners
As it was mentioned above, line gradient type images may not utilize round corners. The hack is to use angle type gradient and set the angle to 90 or 0 degrees to create straight vertical or horizontal gradient.
Creating buttons and horizontal tabs
gradient type of any type except line
Select image width by Size
control and manually specify the desired image height within Alternative Image Side
Now check Round It
and you have your button or tab ready to download.
There of course infinite ways to mix gradient colors, use different gradient types, use split, shift, blow and stripes to create buttons and tabs. Some examples are posted in gallery