Cutting the LED Tape
Each type of LED tape has different cut points. The cut points vary from 25mm to 50mm to 100mm to 166mm, depending on which sort of LED tape you’ve purchased. Each cut point has a line right in the middle of either 4, 8 or 10 solder pads. (4 for single colour, 8 for RGB and 10 for RGBW).
If the LED tape is too long for your requirements, you can simply cut the strip to the correct length along the cut point line using a pair of scissors. You will not have to do anything else as the LED tape circuit will terminate itself.
Soldering the LED Tape
In the same place as the LED tape cut points, you will find 4 solder pads (or 8 solder pads for RGB LED tape, or 10 pads for RGBW tape). These will be marked + and – for single-colour, or +, R, G, B for RGB LED tape.
You can simply solder cable to these pads to create a starter lead to wire back to a transformer or a controller. This can be of any length you require. Or to solder two pieces of LED tape together, you should cut half way through the solder pads on both strips (using a pair of scissors), leaving half a semi-circle on all the pads.
Once that’s done, you can ‘butt’ the pads together to create full circles again, and then solder them together.