While cigarette filter modifications have long been used to increase product appeal and assuage health concerns, tighter marketing restrictions, including plain packaging, have further spurred the growth of filter variants. We explored and assessed experiences and perceptions of smokers who had tried and/or currently use recessed filter cigarettes (RFCs) and firm filter cigarettes (FFCs). In November 2018, we undertook eight exploratory focus groups of Australian adult factory-made cigarette smokers (total n=56). In July 2019, we surveyed 999 smokers aged 18-69 years to quantify ever and current use of these products and associated beliefs and sensory experiences. Focus group and survey findings were consistent. Among 988 smokers who had at least tried factory-made cigarettes, 28.9% had tried FFCs and 11.1% currently smoked these, while 36.4% had tried RFCs and 7.5% currently smoked these. Smokers in both studies believed these filters may reduce harm and that FFCs increase appeal. In the survey, 58.9% of RFC triers agreed these hide the filter's brown stain and 48.9% agreed that RFCs keep harmful substances away from the mouth. Similarly, 58.4% of FFC triers agreed these trap more harmful substances than standard filters. Relative to standard filter cigarettes, more smokers experienced FFCs and RFCs as feeling clean (p=0.03) and more current FFC users experienced these as feeling smooth (p=0.01). RFCs and FFCs undermine plain packaging legislation, which aims to reduce appeal and minimise misperceptions about the relative harms of different tobacco products. Like other filter modifications, these filter variants should be disallowed. © Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.