This lacy tam is worked from the center outwards. The design spirals outward and flows into a ribbed brim. It looks more complicated than it is--if you know how to knit in the round, purl, knit two together, knit three together, and make a yarn over, you can make this hat.
Both charts and written out instructions (in abbreviations) are provided, along with suggestions for modifying the brim size to fit.
A more complete note about gauge: 22 stitches over 3.5 inches [9cm] of ribbing worked in the round on smaller needles. 30 rows over 4 inches [10cm]. Ribbing was unstretched while measuring.
Other materials required include a yarn needle for working in ends, about a yard of smooth, thin yarn for making a lifeline, and a plate for blocking (about 10 inches or 25cm in diameter).