The difference between a good fillet and a wasted one is rarely the angler's skill with a rod. It's the knife and the technique at the cleaning table. A sharp, correctly sized fillet knife and a basic understanding of the fish's anatomy produces clean, even fillets with minimal waste. A blunt, wrong-sized blade produces torn flesh, missed meat along the backbone, and a cleaning session that takes three times as long as it should.
Here's the technique for Australia's most popular species — and the right knife for each.
The basics that apply to every fish
Before getting into species-specific technique, a few principles that apply universally:
Sharp is everything. A blunt fillet knife tears flesh rather than cutting it. Check the edge before you start — it should shave arm hair cleanly. If it doesn't, thirty seconds on a ceramic rod fixes it.
Cold fish fillet better. A fish that's been on ice fillets more cleanly than a warm one. The flesh is firmer and holds its structure better under the blade.
Wet the board. A slightly wet cutting board keeps the fish from sliding. Not soaking — just damp.
One smooth stroke beats multiple short ones. The more passes you make along the backbone, the more flesh you leave behind. Work in long, deliberate strokes.
The blade angle matters. Keep the blade as flat as possible against the backbone — angle it even slightly upward and you're cutting into flesh rather than along the bone.
King George Whiting — use the Whiting knife (185mm flexible)
The King George Whiting is Australia's premier table fish in the southern states — light, sweet flesh with a delicate texture that rewards careful filleting. The bones are small and close together, the flesh is thin, and a heavy hand produces torn, uneven fillets.
Technique:
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Scale the fish first — whiting scales are fine but numerous. Lay the fish on its side on a damp board.
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Make a cut behind the pectoral fin down to the backbone — don't cut through the backbone.
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Turn the blade flat against the backbone and run it along the spine toward the tail in one smooth stroke. The flexible blade will follow the slight curve of the whiting's spine naturally.
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Work around the rib cage with the tip of the blade — short, careful strokes to free the fillet from the ribs without cutting through them.
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Run the blade between skin and flesh from tail to head to skin the fillet. Keep the blade as flat as possible against the skin.
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Repeat on the other side.
Why the flexible blade: The whiting's thin profile means any rigidity in the blade pushes flesh away rather than following the bone. The flexible 185mm King George Whiting knife follows the spine precisely and loses minimal flesh.
Yield: A well-filleted 35cm King George Whiting should produce two clean fillets with almost no waste at the backbone.
→ The King George Whiting Fillet Knife — $235 AUD
Snapper — use the Snapper knife (200mm semi-stiff)
The Australian Snapper (Pagrus auratus) is one of the most widely targeted and prized eating fish in the country. A medium to large snapper has firm, white flesh, a robust skeletal structure, and a significant rib cage to navigate. A semi-stiff blade gives you the control to work precisely around the ribs while the 200mm reach handles the larger frames of adult fish.
Technique:
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Scale the snapper — the scales are large and come off easily. Work from tail to head.
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Make a cut behind the pectoral fin and gill plate, angling down to the backbone.
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Turn the blade flat against the backbone. Starting from the head end, run the blade along the spine toward the tail in a single long stroke. Let the semi-stiff blade push through — don't force it.
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The snapper's rib cage is pronounced. Use the tip of the blade to work around the ribs — a series of short strokes following the curve of each rib until the fillet is free.
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Check the pin bones running down the centre of the fillet. Remove with fish tweezers or needle-nose pliers.
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Skin by running the blade flat between skin and flesh from tail end, using a slight sawing motion as you pull the skin taut with your other hand.
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Repeat on the second side.
Why semi-stiff: A fully flexible blade wanders on a larger, firmer fish — the spine doesn't guide it as reliably. The semi-stiff 200mm Snapper knife has enough rigidity to drive cleanly along a snapper's backbone while still following its natural curve.
→ The Snapper Fillet Knife — $265 AUD
Flathead — use the Whiting knife (small) or Snapper knife (large)
The Dusky Flathead is one of Australia's most popular recreational fish — found from Queensland to South Australia, with particular populations in estuaries, bays, and coastal lakes. Its distinctive flat head and tapered body require a slightly different approach to most round fish.
Technique:
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No need to scale flathead — the skin is often removed rather than scaled.
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Cut behind the pectoral fin down to the backbone.
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Run the blade along the backbone toward the tail. The flathead's flat body means the blade needs to stay very flat — almost parallel to the board — to follow the spine accurately.
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The flathead has a pronounced lateral line of bones running from head to tail along the upper fillet. After removing the fillet, make two cuts either side of this line and remove the bone strip — you'll have two pieces of fillet per side rather than one.
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Skin by running the blade between skin and flesh with a firm, flat stroke.
Knife choice: Flathead under 50cm — the King George Whiting knife. Flathead 50cm and over — the Snapper knife. The flat body profile suits a flexible to semi-stiff blade depending on size.
Tuna — use the Blue Tuna knife (225mm semi-flex)
Filleting a large tuna is a different undertaking to most recreational fishing — the fish is large, the flesh is dense and dark red, and the anatomy is more complex than a standard round fish. A longer, more authoritative blade is essential.
Technique:
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Tuna are not scaled — the skin is removed as part of the filleting process.
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Make a deep cut behind the pectoral fin down to the backbone.
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Run the 225mm blade along the backbone from head to tail in a single stroke if possible — the length of the Blue Tuna knife means fewer passes on a large fish. Keep the blade flat against the spine.
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The tuna's dark lateral meat (the bloodline) runs along the centre of the fillet. Some prefer to remove this before serving — it has a stronger, more pronounced flavour. Cut either side of the bloodline and remove if preferred.
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A large tuna is often quartered rather than filleted whole — each quarter then broken down into loins. The Blue Tuna knife handles either approach.
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Skin by running the blade between skin and flesh. Tuna skin is tough — use firm, deliberate strokes.
Why semi-flex: At 225mm a fully stiff blade is harder to control on the curved anatomy of a large fish. The semi-flex Blue Tuna knife has enough spine for the dense flesh while following the backbone's natural curve.
→ The Blue Tuna Fillet Knife — $295 AUD
After the session — cleaning and storing your fillet knife
Rinse immediately with fresh water after every use. Salt water and fish residue accelerate corrosion even on 14C28N stainless.
Dry completely before storing. A damp blade in a closed tackle box is the fastest way to a rusty pivot or blade — even on corrosion-resistant steel.
Sharpen before the next session. A few strokes on a ceramic rod at 15° restores a working edge on 14C28N quickly. Starting each session with a sharp blade produces better fillets and faster work.
Store in a sleeve or roll. The thin blade of a fillet knife is vulnerable in a loose tackle box — it takes nicks from contact with other gear and the edge dulls from contact with hard surfaces.
Browse the full Fish Fillet Collection →
The Koi Knives Fish Fillet Collection. 14C28N Swedish steel. Designed in Adelaide.
