Hippie clothing is indicative of what was popular when hippies, or as commonly thought of rebel youth of the 60's, were the trend. When you think of hippie clothing, you probably think of bell-bottom pants, tunic tops and sandals. And of course tie-dye.
Tie-dye is probably the most commonly association with hippie clothing. Interestingly enough, it's probably just because of the timing. It wasn't until 1956 that fiber reactive dyes were invented. Before then, dying fabric required heat, strong chemicals, and multiple processes for more than one color. So it's no wonder when fiber reactive dyes were born, the tie-dyed shirt was soon to follow. It meant that not only could a garment easily be made multi-colored, patterns were easier to create as well.
Today, hippie clothing is still well represented by tie dyed clothing, hemp necklaces, and peace signs along with Birkenstock sandals. In its original time, hippie clothing was often made of lightweight cotton and sheer materials. Since then, we've seen the return of many of the popular styles of the 60s. However, it's unlikely we'll ever recapture the spirit and freedom of those who first wore hippie clothing.
Besides tie-dye clothing, other patterns such as those bubble shaped flowers help identify hippie clothing along with patterns and colors that often appear mismatched. In part because of the free-spirited nature and diminished modesty of the era, tops were often low cut or v-neck. For similar reasons, in the late 60s, we saw the emergence of the mini-skirt.
For those with a flair for hippie clothing, there are plenty of sources for buying new. Many stores and online retailers have similar styles and fashions as was popular in the hippie era. Jewelry and accessories are also easily found to accompany the hippie style.