Though blinds are a familiar window covering, if you've never purchased them before, making a choice may seem overwhelming. Many styles and materials are available, and depending on what kind of blinds you need, the necessary measurements and installation will vary slightly. The best choices for you depend upon what you need a blind to do and your preferred style for your room.
The size of the blinds you need depends both on what kind of a window they are for and what kind of blinds you plan on purchasing. If you aren't sure what you want before you go shopping, take a number of measurements and label them before you go. Measure from the top of the window to either the bottom of the window or to the sill to get the inside measurements. Measure the width of the window inside of the frame, at the top, middle and bottom. Get the width of the trim around your window and the width of the sill and apron of the sill, as well. Some blinds are designed to extend beyond the window itself, and you'll want to know how much a blind will overlap the trim. To measure for blinds for glass doors, measure from the top of the frame to the floor. The actual height of the blinds will need to extend from about 3 inches above the top of the door frame to about 1/2 inch off the floor.
Venetian blinds are formed from thin, horizontal slats of material held together with cloth strips or cords. They're very flexible in regard to adjustment; the slats can both move up and down and turn, having the ability to close completely for privacy or to block light. Roman shades and roller shades are made with fabric and offer more complete light blockage than Venetian blinds but less adjustment flexibility; both move up and down only and do not turn. Fabric shades often look more elegant or luxurious than Venetian blinds. Vertical blinds, or track blinds, consist of vertical slats, which can typically be turned to change the direction and intensity of the light and pulled open and closed from side to side.
Blinds are made from a number of materials. Some lend themselves better to certain styles than others. Both wood and faux wood offer a natural look and can be quite elegant. For something durable or more modern, consider aluminum blinds. Fabric is an integral part of some blinds, notably roller blinds, and the color and style of the fabric will be important in your choice. The inexpensive and lightweight nature of plastic blinds gives them appeal as well.
Installation will very slightly depending upon the type of blinds, since some blinds are designed to fit to the inside of a window frame and some are designed to fit to the outside. For the inside, the brackets for the blinds fit along the inner sides of the window frame, as close to the top as possible. Screws hold them to the frame, and the blinds slide into the brackets. For outside of the window frame, you'll need to draw a line at the desired height above the window frame; use a level to ensure that the line is perfectly horizontal. Measure the line and install the brackets with screws at a distance apart from one another that is the same as the width of the blinds. Be sure that they are symmetrical and that each is the same distance away from the window. Brackets usually come with something to keep the blinds from falling out, like a piece of plastic that slides into place to hold the blinds.