If we look at all the techniques we will find that there are some that are only used for lacemaking, but on the other hand there are some that have other uses as well. To the first category belong bobbin lace, needle lace, and tatting. To the second category belong crochet, knitting, macramee, filet and sprang.
Most of the lace that is done by hand today is done in crochet. There are numerous patterns on the market; and in third world countries crochet is done very often for monetary purposes. Only think about the inexpensive crocheted doilies and boxes available at the haberdashery departments and crafts stores. The advantages of crochet are speed, and that you need a minimum of tools, namely the crochet hook. In addition to this there is only one thread to manuipulate, and the movements are easy to coordinate, so that it is easy to learn how to crochet.
Crocheted lace was introduced in the 19th century as a pasttime for better-off women. There was the ideal of the never idle hands, and crochet is very portable, so you could carry your work to your friend and just sit and crochet. But crochet was also done by poor people for gaining a small additional income. During the famine in Ireland some noble women introduced crocheted lace as a means to relieve the horrible conditions under which many people lived. They installed schools, and the lace was marketed in England as well as on the continent. The typical Irish crochet was invented during that time. Some authors even call this kind of lace "real" because it is worked on a pattern that is removed afterwards. Irish lace tried to imitate Venetian lace, but it has its very own characteristics.
Knitted lace was also introduced in the 19 century, together with a way of holding the needles in a new way, which was supposed to look more elegantly than the normal way, but is much slower. During the 30s of the 20th century knitted lace was very much en vogue in Germany, where Erhard Niebling designed wonderful tablecloths and doilies. He himself knitted, and he was able to graph a pattern just from his mind, without reference to a knitted piece. He was a genius as can be seen from his patterns, which are reprinted once in a while by the Burda publishers. Christine Duchrow is another name connected with knitted lace during the 30s in Germany. She published lots of patterns which are also reprinted today.
Needle lace consists (like bobbin lace) of lots of different techniques, which have in common that they are executed by a needle with an eye. Needle lace is the Mother of Lace, although bobbin lace and needle lace were invented about the same time. Needlelace developed from drawn thread embroidery, but later no basic fabric was used, from which threads were cut and drawn out to make open areas, but it was worked on a pattern (often made from cardboard or parchment, sometimes reinforced by fine linnen fabric). On this pattern temporary stitches were made, which anchored the threads which were the basis of the lace. On the basic threads lace stitches were executed to fill in gaps, they were reinforced by additional threads to make a dimensional appearance etc. The temporary stitches and the pattern were removed when the lace was finished. This way of working is characteristic for Irish crochet lace as well. This is the reason why some authors call it a "real" lace.
Battenburg lace is a kind of needle lace, which was introduced during the 19th century. It tried to emulate the tape laces like Bruges and others. It is worked with machine-made tapes that are fixed on a pattern with preliminary stitches. Then the tapes are connected by the needle, and the gaps are filled with needle lace stitches.
Macramee was only seldomly used to work lace. There are some examples from the early 16th century in museums. It seems that in the first lace craze people explored every then known technique that could make an openwork structure. There are only a few examples for patterns in books today, most of them from the turn of the century. Macramee lace is basically Makramee done with fine thread. The macramee fever during the 70s didn't rediscover the lace, so it has never played a distinctive role.
Real Filet lace on the other hand was done very much during the 16th centruy. It consists of a square meshed net, which is embroidered by the needle. Because it originated at the same time as socalled "real" laces it is sometimes included in that term, although it is an emboridery technically speaking. It is possible to knot the net by hand, but today you can purchase machine made net. There is also a technique where the net is embellished while working it, using only netting stitch, but this isn't very old (about the turn of the century).
Sprang is a very old technique, which is almost lost today. It is worked by stretching threads over a frame, which are then twisted about one another until a fabric is created. Sprang is said to be the forefather of weaving.
Again and again people tried to imitate a technique with another. Crochet is the most versatile technique to imitate others. You can find crocheted tape lace, Torchon, Guipure, needle lace, tatting and filet and more. But also tatters tried to emulate needle lace, and you can also work filet with a tatting shuttle. Bobbin lace was originally an imitation of needle lace, but when certain types of bobbin lace were en vogue the same happened to needle lace: it tried to emulate bobbin lace. But imitating as much as you will, every technique will always have its own characteristics, which it can't give up. And in addition to that every lace has some characteristics that are difficult to emulate with other methods. And even the kinds of lace that were mostly used to imitate others have their very own characteristics, and developed patterns that are typical for this technique.
I don't want to forget a last possibility to work lace, because most lace today is made in this way: Machine Lace. Some of the techniques are derived from weaving, so that you have open fabric, but no "real" lace. Chemical lace is "real lace" because it uses a manmade ground fabric, on which cotton threads are stitched by machines. The ground fabric is then removed by chemicals. The famous Plauen lace is made in that way. The other "real" lace made by machine is bobbin lace. It looks very much the same as handmade bobbin lace, but not all structures that are made in bobbin lace can be emulated by a machine (tallies are an example). But in principle it is worked like handmade bobbin lace, but without pricking and pins. The bobbins are moved by the machine. There are lots of different kinds of machine made bobbin lace, from simple and coarse Torchon to finest Chantilly.