I dye the fibres by hand using professional dyes and heat fixing/cold process where appropriate.
Protein fibres (wool, other animals fibres, silk and some manmade fibres) are dyed using non-toxic acid dyes and citric acid. Cellulose fibres are dyed using Fibre Reactive dyes and soda ash. No heavy metals or toxic chemicals are used.
I try to exhaust the dye bath to ensure there is no wastage of dye, and rinse fibres thoroughly. However there may be a small amount of bleeding when you first wash your spun yarn or hand dyed yarns. Blues/teals/jades/turquoise shades, especially saturated hues, are more likely to experience a small amount of bleeding in the first rinses. This is due to the larger molecules and chemical composition of blue/turquoise dye.
I carefully wash my homegrown Gotland fleeces by hand but avoid stripping all the natural oils from it entirely so as to leave a pleasant feel to the fibre.
Some dye molecules can adhere to the small amount of lanolin left behind and whilst on most fibre this is not noticeable, occasionally with deep colours it can leave a trace of colour on your fingers whilst spinning (called crocking). This is normal and not a fault. Hand wash your finished yarn carefully with hot water and detergent to remove the last traces of dye.
I otherwise recommend that all yarns or items made from your handspun are hand washed in tepid water. Do not soak items for a long time and avoid drastic temperature changes. Best results use a detergent suitable for delicates/wool/silk hand washing or a squirt of gentle washing up liquid such as Ecover. I don't recommend the use of specialist non-rinse wool washes as they can sometimes encourage the dye to shift from hand dyed yarns and fibres and cause excess bleeding. Gently squeeze the water from your yarn/garment or if you have access to a non-tumbling spin cycle, spin dry in a mesh bag and dry flat. Reshape or block items whilst damp. Do not weight hand spun yarns as this will alter the yarn/yardage and give misleading results that could adversely affect their use in knitting and weaving.
Most of my fibres/yarns are suitable for hand washing only, some super wash/cellulose/manmade fibre can be washed by machine on a delicate cycle - check the item listing for further washing details. Gotland fibre in particular needs careful washing as it felts readily.