The Singer class 99 sewing machine was introduced in 1911 as a response to the growing demand for a lighter more portable domestic sewing machine that did not need to be used in a special table. The Singer 99 was a sturdy and reliable machine that was easy to use. It became very popular with occasional home users because at 22lbs (10kg), it was more manageable than 'full size' machines and it came in a storage case. The 99 will sew most fabrics from fine delicates to denim or leather and will handle any normal household sewing task with ease. The machines have adjustable tension and stitch length controls. The 99K must always be mounted in some form of base because the underbed mechanism will not allow it to sit directly onto a table surface. Early Singer 99's were sold in wooden bases with a small compartment under the balance wheel to store accessories and bobbins etc. At first they had 'Bentwood' (polished plywood) covers which are now thought of as very desirable. Later models were still fitted in the same wooden bases, but these slid into a mock crocodile suitcase style case for transport or storage. By the end of its production life the Singer 99 was mounted in a plastic base with a clip-on plastic lid, or a soft plastic dust cover.