I am finally getting ready to wire the LED UCL for my kitchen. Based on the LED load, distance from the ac-dc transformer (12V DC) I have calculated I need 18 gauge wire to wire the transformer to LED strip.

Ideally I would like to have white casing, and multi-strand copper wire(the solid core wire is to hard to work with).

What I found out from big box stores is all their low voltage wire is brown, solid core copper wire.

However,they have white, multi-strand copper 18 gauge lamp wire (high voltage).

Can I use this lamp cord instead? If I do, do I risk bigger voltage drop? By how much? Can I calculate the drop? Can I use a lower gauge lamp cord to compensate the extra voltage drop?

Thank you very much!