A swatch is a small piece of something, usually so you can check the color of the swatches against colors in your house. When you have decided which swatch you like, you can buy a larger quantity of it. Swatches usually relate to fabrics.
A tarpaulin is a large piece of canvas that has been waterproofed. Older style tarpaulins were made from fabric waterproofed with wax or something similar, modern tarpaulins are made from woven plastic. Tarpaulins are used to protect things from the weather.
Tartan is a fabric pattern made by weaving different colours together in stripes in both directions. The stripes can be different widths, and there can be lots of different colours, unlike gingham which is made from two colours with equal width stripes.
In Scotland, different families had their own unique tartan pattern.
Tweed is a rough woolen fabric. It is usually quite thick and warm, and has a distinctive herringbone or check pattern in it. Tweed is usually made in fairly dull colors like grey or brown, and is seen as a very old-fashioned fabric.
