Each HTML5 Canvas context contains attributes that can be modified by JavaScript code. Note that attributes are assigned to Canvas contexts, not individual Canvas objects. Attributes for a context are referenced using dot syntax notation. Here is an example: contextName.fillStyle="red". The following attributes show default and other optional values:

fillStyle "black"  
font "10px sans-serif"
globalAlpha 1.0

    Comment: Values shown after attributes are defaults

globalCompositeOperation "source-over"

    Comment: Other compositions are

       "source-in", "source-out", "source-atop",
       "destination-over", "destination-in",
       "destination-out", "destination-atop", "lighter",
       "copy", "xor"
lineCap "butt"

    Comment: Other caps are "round" and "square".

lineJoin "miter"

    Comment: Other joins are "round" and "bevel".

lineWidth 1.0
miterLimit 10.0
shadowColor "transparent black"

    Comment: Other colors include wide variety

shadowBlur 0.0
shadowOffsetX 0.0
shadowOffsetY 0.0
strokeStyle "black"

    Comment: Other colors include wide variety

textAlign "start"

    Comment: Other alignments are

       "end", "left", "right", "center"
textBaseline "alphabetic"

    Comment: Other baselines are

       "top", "hanging", "middle", "ideographic", "bottom"