The name describes the method exactly: you work in lines. Lift the coat into layers and brush every layer until the teeth reach skin, moving across the body in sections, so the comb or brush travels the full length of every hair from root to tip instead of riding across the top. Long-haired breeds make the technique necessary rather than optional. A Maine Coon carries a heavy ruff, long britches, and a plumed tail over a dense undercoat; a Ragdoll wears a silky but abundant coat that tangles behind the ears and under the forelegs. In both, the coat you see is the minority of the coat the cat owns, and grooming that only addresses the visible layer is decoration, not care.
The Technique, Layer by Layer
Set the cat on a surface at your waist height if you can, because line brushing a large cat on the floor wrecks your back before the second side. Lay one hand flat and use it to hold the coat above your working line up and back, exposing a narrow band of coat at the skin. Brush that band outward from the skin in short, gentle strokes, first with the lie of the hair, then lightly against it to lift loose undercoat free, then smooth it down. Lower a finger's width of fresh coat and repeat, line by line, the way you would mow a lawn in strips, until the section is done and a comb passes to the skin without catching. Move to the next section in a fixed order, perhaps left flank, left shoulder, chest and ruff, then turn the cat and repeat on the right, finishing with britches, belly if tolerated, and tail. The exposed skin along each line is also your inspection strip: look for flakes, redness, parasites, and the pale felted beginnings of a mat while they are still teaseable with fingers and a comb.
Why Surface Brushing Fails the Undercoat
Skimming a slicker brush across the top feels productive because the cat looks sleek afterwards, but the physics are against you: the teeth ride over the guard hairs and never enter the undercoat, where loose hairs are shedding into hairs still rooted. That buried mixture compacts with body warmth, movement, and a little moisture into felt, especially where friction helps it, the armpits, the britches, the belly, behind the ears. By the time a mat shows at the surface, it may already be a flat, skin-tight plate. Line brushing defeats the process at its origin, because every layer is separated and cleared before compaction begins, and any snag is met while it is a knot of a dozen hairs, not a thousand. This is also why the comb test matters: a comb that reaches skin everywhere is proof, and a comb that skates is a warning, whatever the mirror says.
Pacing a Session for a Big Cat
Maine Coons and Ragdolls are large, patient cats by reputation, but patience is a budget, not a personality trait, and a full line-brushed session can take thirty to forty minutes on a big adult in heavy coat. Spend the budget wisely: split the cat into halves across two days, or do one side per session on a rota, keeping the friction zones on a shorter cycle than the easy back and sides. Watch the tail and the skin: a lashing tail, twitching along the back, or ears rotating back mean the budget is nearly spent, and finishing the last line tomorrow beats teaching the cat that grooming ends in a struggle. Keep tools ready before the cat arrives, work at the same calm time of day, and end with the part the cat enjoys, often the cheeks and chin. Consistency across the household matters as much as technique, and that is where KinsLe earns its place, since shared Care Teams notes can record which sections were finished on Tuesday so the next person starts on the right flank, not the same one again.