A sheet of good birch ply costs real money, and the difference between a careless layout and a considered one is routinely a whole extra sheet on a kitchen's worth of cabinets. Here is what actually moves the number.
First, what yield is realistic?
Yield is the fraction of the sheet that leaves as finished parts. One hundred percent is impossible — kerf alone guarantees that. Some honest reference points:
- 60–70% — typical for a mixed list of awkward sizes with grain constraints
- 75–85% — good, and achievable on most cabinet work
- 90%+ — only when your parts happen to divide the sheet neatly
If a tool promises you 95% on an arbitrary cut list, it is either ignoring the blade or producing a layout you cannot cut. Be suspicious of both.
1. Group parts by a shared dimension
The single biggest win. If eight parts share a height, they form a band across the sheet with one rip and then crosscuts — almost no waste between them. Parts of wildly different sizes scattered across a sheet leave slivers everywhere that nothing else fits into.
When you design, reuse dimensions deliberately. Making every shelf 11 1/4" deep instead of "whatever looks right" costs you nothing and can save a sheet.
2. Be honest about grain
Grain locking is expensive. A part that must run one direction cannot be rotated to close a gap, and every locked part narrows the solver's options.
So lock what genuinely needs locking — visible faces, door panels, anything where the figure will show — and release everything else. Cabinet backs, shelf cleats, drawer bottoms, hidden stretchers: nobody will ever see which way the grain runs. Every part you unlock is a part that can turn sideways and fill a hole.
3. Trim only what needs trimming
Squaring up all four edges of a sheet is a habit, not a law. A 1/4" trim on all four sides removes 1/2" from each dimension before you start.
Inspect the sheet. If two edges are clean and square, trim two edges. That reclaimed half-inch is often exactly what lets one more part onto the sheet.
4. Cut the big parts first
Large parts have few places they can go; small ones have many. Place the large ones while the sheet is still open, and let the small parts fill in around them.
Doing it the other way — small parts first — fragments the sheet into pieces too small for anything large, and then a 30" panel needs a new sheet even though the material exists.
5. Keep your offcuts, and use them first
The cheapest sheet is the one you already paid for. A rack of offcuts with their sizes written on them will cover a surprising share of small parts — drawer bottoms, cleats, jigs, spacers.
The discipline that makes this work is writing the dimensions on the piece as you rack it. An unlabelled offcut pile becomes firewood; a labelled one becomes inventory.
6. Buy the sheet that matches the job
A 4×8 sheet is the default, not the only option. If your parts are 24" square, a 5×5 Baltic birch sheet divides far more cleanly and you may pay less per usable square foot even at a higher sticker price.
Work out the yield for both before buying. Cost per usable square foot is the number that matters, not cost per sheet.
7. Let the layout be ugly
A tidy-looking layout in neat rows is often a worse layout. The efficient one usually looks a bit chaotic, with parts turned and tucked into gaps.
What matters is not whether the drawing looks orderly — it is whether every cut runs edge to edge so you can actually make it, and how much of the sheet leaves as parts.
The part worth handing to software
Every item above is a judgement you make once. The packing itself is a genuinely hard combinatorial problem that humans are bad at and computers are good at, and it has to be redone from scratch every time you change a quantity.
Kesim runs the search many times over with different orderings and keeps the best result, while respecting the kerf, the trim, the grain locks, and the fact that your saw can only cut in straight lines from edge to edge. You bring the judgement; it does the arithmetic.