or how to knit a "Picture Afghan"
Something I enjoyed in crochet - and which frustrated me with knitting was the ability in crochet to easily create filet mesh "pictures". done in a heavier yarn they make nice afghans. Or filet mesh geometric patterns made complex looking but mindless-to-work patterns.
Which was a reason I purchased 'A Gathering of Lace'. In that book there is a technique for filet knitting - they use it in the round to work a graphed picture of a unicorn.
To use the technique in back and forth knitting (such as for a blanket or afghan or laprobe or wall hanging or door screen or window shade) is a little more complicated - but I worked it out last year to knit a dragon stole for my niece's Mother-in-law.
The technique uses 2 stiches x 3 rows for each square in a graphed pattern. The meshes are either "filled" or "empty". You're aiming for a stockinette fabric - so in addition to the 2 stitches per square you also want to allow for some edge stitches to prevent curling and you also have to add 1 stitch per row to make things balance out. or subtract one edge stitch.
(each square worked "loans" a stitch to an adjacent square to complete it)
But since it takes 3 rows of knitting to work a row of graphed squares, you are working every other row of squares in opposing directions. (confused yet? believe me - I was!) So odd rows are worked one way and even rows another...sorta
Assuming you are starting your work at the bottom right corner of a graph, working right to left across the first row:
an Empty mesh is worked: YO, k2tog
a filled mesh is worked k2
Row ONE-B (you are now *READING* left to right = still on the first row of the graph)
an empty mesh is worked p1, slip YO purlwise, YO [the two yo's should end up as parallel threads across the needle}
a filled mesh is worked p2
this is a "wrong side" or Purl row. Read row two of the graph from left to right.
An empty mesh is p2tog, YO
a filled mesh is p2
Row TWO-B: reading row two of the graph from right to left
an empty mesh: with yarn in front slip the YO purlwise, k1
a filled mesh: k2
Row TWO-C : purl across
I'd use a 6mm needle with a sport weight or 9 mm needle with a worsted weight for an afghan. It works up quickly and opens up a lot, so your chooice of needle sizes might be smaller for the same weight yarn. (I actually worked the dragon stole in lace-weight on 6 mm needles)