When choosing string lights for a deck or patio, it is easy to first think about length and the number of bulbs. But in practice, it is often the way the string lights are going to be installed that determines which choice is best.
At LY Sweden, we think round cable is often the most natural choice in many common installations. It is easy to work with and works well when the bulbs are meant to hang downwards, both for freer hanging installations and along walls, posts and railings. Flat cable is best suited for ceilings or underneath a structure where it can be installed with the flat side facing downwards and the bulbs hanging straight down.
If you want a simple starting point, this is how we usually think about it:
In many home environments, round cable is the easiest option to work with. It works well when the string lights need to:
That is why we often recommend round cable for decks, patios, pergolas and other environments where the installation needs to be simple and flexible.

Flat cable should not be chosen just because something is a fixed structure. What matters is that the cable can actually be installed in the right way.
We think flat cable is best suited:
In those situations, it looks both neat and natural.
On a deck or patio, most people want a warm and pleasant light, not the brightest possible lighting.
That is why we usually recommend 1W first.
2W works if you want a bit more light over a larger area or, for example, above a dining table.
3W is best when you want a clearer effect or have a larger and darker environment.
For most patios, 1W is the safest choice.
We almost always think a warm light works best outdoors.
2200K is often what we recommend first, because it gives a soft and atmospheric feel.
If you want an even warmer look, amber can be beautiful.
If you want a slightly clearer, slightly whiter warm light, 2700K may be a better fit.
That depends on how the string lights are going to be installed. If they are going to hang freely over an area, between posts or over a more open part of the patio, wire is often a good idea. If they are going to be mounted close to a wall or ceiling, it is usually not needed.
We usually think of it like this:
If we are to give one simple recommendation for decks and patios, we usually say:
That usually gives you a very good starting point.