The ribbons that have two rows of LEDs on their board are called double-row, three rows - three-row, and so on.
When manufacturers have reached the maximum power and diode density of single-row LED strips, and the power is still not enough, came up with a double-row ribbon.
The production of double-row belts is somewhat more expensive because the equipment has to be reconfigured, the double-row and more boards have to be designed separately. The double-row tape is nothing more than a marketing ploy. In essence, two parallel tapes are no different than a double-row tape.
We always prefer the variant with two different belts, because it is often possible to save a little money for the same efficiency and at the same time increase the reliability of the construction.
— We have already written about the cooling of the LED strip and why it is important (see LED profiles), so placing the strip at a small distance from each other, whether 1mm you already increase the heat spot, thereby prolonging the life of the LED strips.
— If you have for some reason will fail one segment of the LED strip, then replace the segment on a single-row strip, which is at least twice as cheap as a piece of double-row tape.
— When you design MIX-White or RGB+W lighting, there are many more varied and unique options, better suited to your personal requirements.