Several countries are known for producing high-quality artist canvas, each with its own strengths and characteristics. Some of the top countries known for producing artist canvas include:

1. Belgium: Belgian linen is considered some of the best in the world for its fine weave, strength, and durability. It is often used by professional artists for high-quality paintings.
2. Italy: Italy is known for producing fine cotton canvases, often with a medium to fine weave. Italian canvas is prized for its smooth surface and quality construction.
3. France: French canvas, particularly from the town of Arles, is highly regarded for its quality and texture. French linen canvases are often preferred for their strength and durability.
4. United States: American canvas, especially cotton duck canvas, is popular among artists for its affordability and quality. Some American manufacturers produce high-quality, professional-grade canvases.
5. India: Indian cotton canvases are known for their affordability and good quality. They are often used by artists looking for a balance between quality and cost.
6. China: While China is known for producing a wide range of canvases, the quality can vary. Some Chinese manufacturers produce high-quality canvases that are suitable for professional use.

Ultimately, the best artist canvas depends on the artist's preferences, painting style, and budget. It's essential to consider factors such as weave, weight, texture, and material (linen or cotton) when choosing a canvas for a specific artwork.