A pattern I scanned from an Escher woodcut and then edited so that it tessalated by rectangles rather than by parallelograms. You might notice that the pattern contains two distinct birds of each colour rather than one.
Another scanned Escher woodcut, this one much
easier to do because the pattern is so obviously self-repeating.
Next.
I have to admit that I stole this image from another site and messed around with it until it was black and white. I hope you like it nevertheless.
This is a an example of a bowtie pattern, ie. one where a symmetrical section has been added to a rectangle and also rotated by 90° and removed from the rectangle. In this case the section is an arc of a circle.
The classic bowtie pattern. The reason for the nomenclature requires no further explanation, I hope.
This dart-like pattern is an an extreme example of a bowtie pattern, one where the section removed meets in the centre of the rectangle.
Since Penrose tiling never repeats this pattern breaks the rules at the edges of the tile but still tiles the plane using only the same two rhombi.
This is a quadrilateral version of a triangular pattern that Escher once saw in a Morroccan temple and copied in to woodcut form. However this version here is designed directly on the computer rather than being scanned. The triangular version is rather harder to achieve.
But not impossible as you can see. This version is also designed directly on the computer but it is a bit rough at the edges because it had to undergo some hand and eye guided rotation. Still nice, though.
This pattern is the only one (so far) on this page where a single example of the tile shape forms the basic element of the tessalation. This sentence is currently under construction!