Spaces in most patterns I've used are 2 stitches wide, with a stitch (usually a dc) on either side acting as the vertical "bar". You can vary this to make the spaces larger, using treble stitches and more chains if you want to experiment. See the photo at right for a visual image of how the stitches look (although this photos is sideways....oops!)
First, crochet a chain as the base. You will need to count the squares along one edge (usually the lower edge) of the pattern. Multiply this by 3 and then add one extra stitch. This is your base chain. Be sure and note which is the last chain in your base chain.
You now turn your work and work back again over the base chain. What you do now will depend on your first block/space. If you need to make a block first, as you would in the pattern on the left, you'd need to crochet 3 ch to turn, then crochet a dc in the last chain of the base chain you made previously. Now make dcs in the next 3 chains of the base chain. This is one block (2 dc in the center with a dc on each side acting as "bars."
If you need to make a space first, sc 5 stitches to turn, (3 stitches count as a dc and 2 stitches to bridge the space. Now made a dc in the 4th chain on the base chain. This makes the first space: an open space 2 stitches wide with bars on either side.
Now that you have begun, you will continue to make blocks of 4 dc (2 dc in the center to fill in the block, and a dc on each side as a bar).
Spaces are made with a dc made into stitch below, then 2 ch stitches to bridge the space, (skip 2 stitches on the row below) then dc into the next stitch below.
At the end of each row it is necessary to chain a few stitches to turn. Chain 3 stitches if you will be making a block first; 5 stitches if you're making a space first.
Each row is worked, of course, exactly over the one below it. Filet makes beautiful patterns, is easy to do, and looks great framed!
This is part of a larger filet piece of roses.
