New macrame makers, sensibly, focus on learning the knots — the square knots, the half hitches, the patterns — and treat the cord as a neutral material that any reasonable choice will do. Then their finished piece does not look like the inspiration that drew them in, and they assume their knotting was the problem. Often the knots were fine; the cord was wrong. The cord you choose — its type, its thickness, and how it behaves — determines the look of a finished macrame piece more than your knotting technique does, and choosing it wrong disappoints even with perfect knots.
Why the cord defines the look
Different macrame cords behave completely differently. Some types hold their shape crisply so the knots stand out sharp and defined; others are softer and drape, giving a flowing look; and some can be brushed out into a soft fringe while others cannot. The thickness changes the scale and feel of everything. So the same pattern, the same knots, in different cords produces completely different results — crisp and structured, or soft and flowing, or fringed and bohemian. The character of a finished piece is largely set by the cord before a single knot is tied, which is exactly why beginners who nail the knots but chose the wrong cord end up with something that does not match what they pictured.
Why cord gets treated as an afterthought
Because the knots are the visible skill being learned and practised, so they get all the attention, while the cord seems like just the stuff you knot — a commodity. Beginners do not yet know how dramatically cord choice changes the result, so they grab whatever cord is handy and pour their focus into technique, then cannot understand why their well-knotted piece looks wrong. The cord was quietly the bigger decision all along.
The takeaway
Take cord choice as seriously as knot technique — more seriously, for the look. Decide the finished appearance you want, then choose the cord type and thickness that creates it, because the cord defines whether your piece is crisp, draping, or fringed far more than your knotting does. Good knots in the wrong cord disappoint; ordinary knots in the right cord can look wonderful. The cord is the whole look, so choose it on purpose, not as an afterthought, and your knots will finally give you the piece you set out to make.