Shadow and gradients slow page load...why?

Question

I have read how shadows and gradients slow down a web site, and that you should replace them with (essentially) screen shots of the same (i.e. looks the same, but not using the shadow or gradient feature of iweb).
I understand that larger photos (etc) slow down a page load, but I don't follow why these do. I am curious for an explaination. It would seem intuitive that the apple folks would publish a web site in a way that did not cause this (i.e. covert shadows and gradients to jpgs or something).
thanks
bob

Answer 1

Shadows and gradients generally actually don't cause professional designers any issues, how you design it and what file format is important, most produce high quality images with a low impact to the web page load time. I have been designing for over 20 years and quite like iWeb challenges .
iWeb however does something quite different, it adds to an existing image, mainly using javascript which slows the rendering and page loads. iWeb works great for non professionals as it's dreadfully poor from a site point of view, remember iweb is a toy in the software world of web design tools, so enjoy it for what it is..
A simple way to prove is to design a single page in iWeb and the another using, say, Dreamwever, look at the rendering/load times.....