The chart alongside ,courtesy of Schmetz,is available at all times in my eBay shop,which is at

http://stores.ebay.co.uk/sewing-paradise_W0QQsspagenameZMEQ3aFQ3aSTQQtZkm

and neatly avoids my having to write out all the details on which needle to use for each job!

Why  is it so important to use the correct needle for each fabric? Perhaps the main reason is that a needle which is too light may break,and either fly towards your face or jam the lower bobbin mechanism. The latter will usually upset the machine timing,and it can be an expensive and difficult thing to put right. A needle which is too heavy will danage fine fabric and make unsightly stitches. A plain needle will snag in knitted fabrics,whereas a ballpoint needle (the ball is very tiny!) will run along very smoothly!

When should you change your needle? At the very first sign of hesitancy in piercing the fabric! If you hear a plop-plop sound as you sew,or your thread appears to be ravelling,you have left it much too late! Do remember that even the very best machine needles only cost pence each,in comparison to your sewing machine,which probably cost hundreds!

If you have the correct and new needle for the fabric,and you are still struggling,perhaps because the material drags on the bed or has a coating which the needle does not like,take a tip from the manufacturing trade and use a little squirt of silicone spray on the needle and machine bed-it can work wonders!

Which make of needle should you use? The trade would consider Schmetz needles to be the best in the world,both on quality and sheer variety for every application. If you are purely a basic sewer and need to economize a little,Organ needles from Japan have a very good name. Any needle offered by the major sewing machine manufacturers will be reputable,and will have actually been made by a major needle manufacturer. All domestic machines have needles with one flat side,so beware of cheaply offered industrial needles which are usually totally round and often also of the wrong length for a domestic machine! Also remember that the ridiculously cheap tiny machines ,often offered in the press,usually take a specific needle which is not easily obtainable!

I hope that this broad outline has been of use,and if I can help with a specific problem,please feel free to ASQ me from any of my listings!