Fabric might seem like the last thing you should purchase online. After all, how can you accurately gauge texture, drape or finish from an image on your screen?
You can't. But I'll bet you've bought items made from fabric on eBay, and not had the same concerns. Why? Because you searched for 'Ikea pillowcases' or 'Monsoon skirt' and felt you had a pretty good idea what the resulting items would be like. Familiarity is key; if you aquaint yourself with different types of material it'll be less of a gamble buying them off the 'net.
First things first, what's your project? We can safely assume it will fall under one of the following headings: Home furnishings, Clothing, Quilting/Patchwork, General crafting.
Home furnishings first... here's what you're looking for:
Cushions and pillows - sofa/chair type. The key points are medium to heavy weight fabric, without stretch. Cotton drill, corduroy, upholstery fabric, velvet, suedette or leatherette are all winners. Just bear in mind that not all of these are washable so you need to be more selective and ask sellers questions if you need something you can toss in the washer/dryer.Cushions and pillows - bedding type. You're looking for light to medium weight, without stretch. 100% cotton is best. For cosy children's bedding, particularly in winter, you could consider brushed cotton, flannel or fleece.
Curtains. Medium to heavy weight fabric without stretch. You'll also need lining fabric, which can be 'blackout lining' if you want to completely keep light out of a room. Cotton drill, corduroy, upholstery fabric or simple cotton/polycotton (especially for a child's bedroom) are all appropriate.
Table coverings. These should to be made of something non-stretchy that's easy to wash and iron. Cotton, polycotton and calico are all good options. For water-resistance oilcloth (plastic coated cotton) is a good option. If protection from heat is required PVC table protector fabric can be easily slid under a pretty cloth.
Next up, clothing. The fabric you need will depend on the occasion for which you're creating the garment. There may be some overlap but in general a fabric will lend itself either to formal or informal, to warm weather or cool. Universally you'll want something that is easy to care for (washable, tumble-dryable, easy to iron), comfortable against the skin, and with or without stretch. You'll find a huge variety on eBay: suiting, satin/silk/brocade, cheesecloth, denim, twill, corduroy, crepe, fleece, jersey (or 't shirting') and 'sweatshirting'. Requesting swatches or popping to your nearest department store for a surruptitious feel of the various types can be invaluable.
Quilting/patchwork. Generally only quilting cotton (medium weight, 100% cotton without stretch) is used. This may be sold as yardage, in metres, or by the 'FQ'/'Jelly Roll'. Brushed cotton or flannel makes extra-soft quilts for children.
FQ means ‘Fat Quarter’. These are quarter-yard cuts (18 x 22” or 45 x 55cm) cuts of fabric.
Jelly Rolls are sets of 40 small strips of fabric. They will generally be from a single fabric manufacturer and coordinate, so you don't have to hunt for prints that 'go'.
Quilt filling (the middle or padding) is called ‘batting’ or ‘wadding’. It's sold in a variety of pre-cut bed sizes from ‘crib’ to ‘king’ or you can buy it by the metre for use in other projects.
Quilt backing can be cotton or muslin. It comes wider than standard cotton to allow you to back full-size quilts with a single piece.
General Crafting... let's split this into two main areas:
Children's crafts. You'll want material that is hardwearing, non-slippery and without stretch. Felt can be glued as well as sewn. It is not washable but comes in a range of fun colours and can be bought as squares or by the metre. Self-adhesive felt is also available. Polycotton is inexpensive option for young stitchers.
Gifts and miscellaneous. Here we're talking about projects such as bags, aprons, zipped pouches, glasses cases and tea cosies. Quilting fabrics are always appropriate; good quality and easy to work with, they can be found in thousands of different prints, from classic florals to novelties.