Many people are seeking privacy these days and if you are one of them then your best choice in window treatments would definitely be shades. Shades provide total darkness while blinds do not. When buying shades for your windows you have to make sure they fit exactly to the window, with no chance of any light shining through. Shades are made from vinyl which is a very tough fabric and very hard to see through.
In the past years, shades have slightly gone out of style but many people still use them. With blinds because they have gaps in them you may be not be able to block out all the light. As with shades you have to make sure the blinds fit tightly on your windows.
Window blinds are very popular these days and people don’t really seem to mind if there is a gap in them or not its the style they are after. But if privacy is a main concern you could put shades under your blinds. This way you would get two birds with one stone as they say, keep out the light and still be in style.