The chair sets the brief
A deep armchair, a high-backed chair and a recliner place a reader in different positions. Measure the space beside the chair with somebody sitting in it normally. Include the arm height and the location of the book rather than taking the empty seat as the only reference. The lamp has to serve the person, not simply fill the corner.
If the chair reclines or rocks, check its full movement before choosing a lamp position. A base that is clear while the chair is upright may become an obstruction later. Keep the lamp, lead and nearby table outside the moving area. This also helps prevent the light being knocked every time the chair changes position.
Consider which side is available. A floor lamp tucked behind a shoulder can direct light onto a page without occupying the table beside you. But a very high chair back may intercept the beam. In that case a longer adjustable arm, positioned to the side within its designed reach, can be more useful than a taller upright lamp.
Understand the reach
Overall height tells you surprisingly little about where a reading lamp can put its light. Look for the head's adjustment range, the distance from the upright to the shade and the footprint of the base. An angled publicity photograph may disguise how much floor space the lamp occupies when it is actually aimed at a book.
Mark the base's approximate footprint with a loose piece of paper during planning, then remove it when you finish. Can you still place your feet comfortably and move around the chair? An arc lamp may reach far across the room but need a substantial base behind it. A compact task lamp may be a better fit beside a small chair.
Try to see a display model from a seated position. Check whether the head can be adjusted with a straightforward movement and whether it holds its position. Some lamps have intentionally limited joints. They should not be pushed beyond those stops to make a particular corner work.
Keep the source out of the normal view
A focused beam is useful, but an exposed bright source near your face can make the arrangement unpleasant. Sit with the book at its natural angle, then look up into the room. You should not have to hold a strained pose to avoid the bulb. Test both the upright reading position and the more relaxed position you use later in the evening.
The shade may hide the source from you while exposing it to somebody on the sofa opposite. Walk around the seating group and check those views as well. Moving a lamp slightly behind the chair or changing its angle can solve the problem without reducing the light on the page.
Avoid judging the beam by shining it at a bare wall alone. Bring an ordinary paperback and, if relevant, a magazine with glossy pages. The pool needs to cover the reading area without a distracting bright reflection. A lamp that lights half the spread makes you move the book instead of allowing you to settle.
Consider the switch and the socket
Find out where the control is before purchasing. A foot switch can be convenient in an open spot but awkward behind a heavy chair. A control on the stem may be easier to reach, provided it is not positioned above your comfortable reach when seated. A remote needs a predictable home or it becomes another thing to search for.
The cable should reach along a protected route without being trapped by chair legs or stretched across the way in. If power is on the wrong side of the room, reconsider the furniture arrangement. Moving the chair a little can be a better long-term answer than hiding a lead beneath the rug.
Leave some surrounding light
The reading lamp need not light every surface. It does, however, belong in a room where you will look up, put the book down and walk away. Try it with the table lamp or main room light you normally use, then assess the complete evening arrangement. A good reading corner has enough light for its purpose without demanding that the rest of the room disappear.
Only after those checks should finish and shape decide between the remaining options. A slim brass stem, painted metal shade or timber detail can connect the lamp to the room, but none compensates for a switch you cannot reach or a base sitting where your feet need to go.
