Removal of tobacco industry branding from cigarette packs may reduce their appeal. Adding graphic warning labels (GWLs) should enhance this effect. We investigate whether willingness to pay for various packaging designs changes after 3 months' use of: (1) US branded packs without GWLs (US), (2) non-branded packs without GWLs (Blank), and (3) rotating non-branded packs with GWLs (gangrene; throat cancer; neonatal baby) covering >75% of pack (GWL). Californian adult daily smokers not planning to quit (n=287; 56% female; mean age=39.6) completed a discrete choice purchase task before and after 3 months' experience using one of three packaging options. Conjoint analysis and pre-post modelling evaluated the change in importance of pack attributes and willingness to pay for US, Blank or GWL (blindness; teeth; gangrene) pack designs. Price determined ~70% of purchase choices, while pack design determined ~22%. Irrespective of intervention arm, US packaging generated appeal valuations compared with Blank packaging, while GWLs consistently provoked strong aversive valuations at baseline and follow-up. Compared with the US pack arm, using GWL packs for 3 months decreased willingness to pay for US packaging (β=-$0.38, 95% CI -0.76 to 0.00). Wear-out effects were detected in the discount needed to willingly purchase the gangrene-GWL pack (β=$0.49, 95% CI 0.16 to 0.82) and Blank pack (β=$0.42, 95% CI 0.09 to 0.74) but not for GWLs (blindness, teeth) not used in trial. Compared with US branded packs, the negative valuation of non-branded GWL packs attenuates with even 3 months' use but does not generalise to non-used GWLs. This suggests that GWLs should be regularly refreshed. The appeal valuation of industry imagery suggests that the US plan to retain such imagery on packs may ameliorate the effect of GWLs.