The 4 main types of women’s obis are:
Nagoya
Fukuro
Maru
Hanhaba

• Nagoya obi usually have the sash section ready folded and they open out to full width at the tare (rear knot end section). Some Nagoya obis are hassun Nagoyas, that is, they have no stiffening core inside, making them a bit softer and easier to tie.
• Fukuro obis are not pre folded and require the sash section of their length to be folded in half when putting them on. Fukuro are also thicker and heavier than nagoya obis. 
• Nagoya & Fukuro and most nagoya (if the repeat pattern type) and fukuro obis have the pattern only one side of the fabric and are plain on the inner side. They are also often rokutsu, which means only patterned along 60% of the length on the outside, the other 40% is plain and is hidden underneath when the obi is wound twice round the waist. Rokutsu are also usually patterned on only one side. One that is patterned along 100% of its length is called zentzu. 
• Maru obis are the most formal ones and have the same pattern on both sides and are zentsu obis, that is, the pattern is along the entire length, even the hidden areas. They are particularly heavy and vastly expensive obis. Maru obis are rarely worn nowadays, usually reserved for brides. They are very vollectable, as they are becoming rarer, and offer a lot of fabric for remaking, as they are wider and patterned along their entire length on both sides
• Nagoya, fukuro and maru obi can be tied at the rear in a variety of musuba (knots) but the most popular and easiest is the taiko knot. For this and many other knots they require other items; a makura pad for inside the top of the knot, an obiage to help hold the knot in place and to cover the makura and hold it, and an obijime cord to tie around the centre of the sash and through the knot, to hold it in place. A fourth item is often used too, an obi mae ita (obi ita), which is a board that is slipped behind the front of the sash to keep it firm and avoid creasing as one moves.. The obijime cord is sometimes decorated with an obidome (a special obi ‘brooch’ the cord is threaded through) at the centre front. All these items are usually bought separately.
• Hanhaba obi are lightweight, informal obis and are usually tied in cho cho musuba (bow knots) and worn with casual yukata kimonos. Yukata are worn at summer festivals and are also worn as house robes.
• 2 Part obi have become popular with those short of time or skill at tying obi. They are most popular as 2 part hanhaba obi, for casual wear with kimonos like yukatas, or as 2 part Nagoya obis, with the knot section pre-shaped in the taiko knot style. Some two part ones do not have the knot section pre shaped but it is still easier to fold into shape and position than if the sash section and knot section were all one, untied piece.
• Obi rear knots, whether on pre-shaped, 2-part obis or one piece obis, the knots are are held in place using an obiage and an obijime and, if a taiko style knot, is also padded out at the top with an obi makura; all of these items are bought separately, although one can improvise with them. However, a makura is not required for a hanhaba obi nor for a pre shaped bow knot obi.

Do not wash obi. If you have a dry cleaner you trust, ask their advice about dry cleaning but all cleaning is done at your own risk.