Not every famous painting can be turned into a numbered canvas, and the ones that fail do so for a reason that is worth understanding. It is the same reason that explains why your own kit looks the way it does.
A numbered canvas is built entirely out of edges. Every region has a boundary, and inside that boundary one flat color. A painting that is itself built out of clear shapes converts beautifully. A painting whose whole effect depends on there being no boundaries anywhere cannot be converted at all, only approximated badly.

The ones that work
Hokusai, The Great Wave off Kanagawa
Katsushika Hokusai made this around 1830 to 1833 as one of the Thirty-six Views of Mount Fuji, and it was a woodblock print rather than a painting. That is exactly why it converts so well: a woodblock print is made by cutting flat areas of color from separate blocks, so the image already exists as bounded regions of solid color. Numbering it changes almost nothing.
Klimt, The Kiss
Gustav Klimt painted it in 1907 and 1908 in oil and gold leaf, and at 180 centimeters square it is close to a two-yard cube of a picture. The robes are made of flat rectangles, spirals and circles set against a gold ground, which is pattern rather than modeling. Everything except the two faces is a natural fit for numbered regions, and the faces are the part that reproductions usually get wrong.
Van Gogh, The Starry Night
Painted in June 1889 while Van Gogh was at the asylum at Saint-Remy. His mature technique is discrete, visible strokes laid side by side rather than blended into one another, which is very nearly a numbered canvas already. The swirls in the sky are the most-copied passage in the history of painting for exactly this reason: they are separable.
Van Gogh produced somewhere around 860 oil paintings in roughly a decade, most of them in the last few years of his life. We have written about this one specifically in our piece on The Starry Night.
Seurat, A Sunday Afternoon on the Island of La Grande Jatte
Georges Seurat spent 1884 to 1886 building this picture out of small separate dots of color, on the theory that the eye would combine them at a distance. It is the closest thing in art history to the logic of a paint by number kit, made sixty-five years before the first kit went on sale.
The ones that cannot work
Leonardo, Mona Lisa
The whole achievement of the picture is that there are no edges. Leonardo built the face out of dozens of translucent layers, each fading into the next with no visible boundary, so that the corners of the mouth and eyes dissolve rather than stop. Divide that into numbered regions and you get a face made of flat patches, which is precisely the effect Leonardo spent years eliminating.
Vermeer, Girl with a Pearl Earring
Painted around 1665. Same problem, plus a second one: the picture depends on a handful of very small, very bright highlights against a dark ground, and a numbered region cannot reproduce the softness of the light around them.
Anything by Rembrandt
Rembrandt's subject is essentially light in darkness, and most of his canvases are a narrow band of near-blacks with the modeling carried by tiny shifts within them. On a numbered canvas those become a set of pots you cannot tell apart.
Monet is the interesting case
Claude Monet painted somewhere in the region of 250 water lily canvases at Giverny over the last thirty years of his life. In principle they convert: he worked in broken, separate strokes of color, so the regions exist.
In practice they make a hard kit. The palette is deliberately close-toned, so you end up with a dozen pots of nearly the same violet-green and no reliable way to tell them apart. If you attempt one, work a single number all the way across the canvas before opening the next pot. Related colors separate when laid side by side and are impossible to match from memory. Our piece on the water lilies goes into what he was actually doing, and Cezanne is a related case for anyone drawn to that period.
What copyright allows
Everything named above is old enough to be in the public domain, which as a rule of thumb means the artist died more than seventy years ago. Hokusai, Leonardo, Vermeer, Van Gogh, Seurat, Klimt and Monet are all comfortably past that line, and anyone may reproduce their work.
Twentieth-century art is a different matter. Work by artists who died within the last seventy years, and by every living artist, is still in copyright, and reproducing it commercially requires permission from the estate. Kits of famous modern paintings do exist and many of them are not licensed.
The same applies in reverse to custom work. We can turn your own photograph into a numbered canvas, but we cannot make one from an image you do not have the rights to, which includes copyrighted artwork, film and television characters and professional photographs taken by someone else.
What we make instead
We do not sell reproductions of famous paintings, and it is a deliberate choice rather than an oversight. Our designs are licensed original artwork by contemporary painters who are still working, among them Kim Norlien, Darrell Bush, Abraham Hunter, Judy Buswell and Hayden Lambson. Licensing the original rather than copying a print is the difference between a real painting on your wall and a generic one, and it is why the artist is named on every product page.
If a specific picture is what you are after, the more direct route is a custom canvas made from your own photograph, in 12x16, 16x20 or 18x24. And if you would rather start from the artwork, the designs are in the full collection.