The index typewriter was briefly popular in niche markets. Although they were slower than keyboard type machines they were mechanically simpler and lighter, they were therefore marketed as being suitable for travellers, and because they could be produced more cheaply than keyboard machines, as budget machines for users who needed to produce small quantities of typed correspondence. The index typewriter's niche appeal however soon disappeared, as on the one hand new keyboard typewriters became lighter and more portable and on the other refurbished second hand machines began to become available. The last widely available western index machine was the Mignon typewriter produced by AEG which was produced until 1934. Considered one of the very best of the index typewriters, part of the Mignon's popularity was that it featured both interchangeable indexes and type, allowing the use of different fonts and character sets, something very few keyboard machines allowed and only at considerable added cost.