This study presents acoustic and electro-magnetic articulometry (EMA) data forthe vowel /i/ in pre-boundary position in French. The boundaries examined are the Utterance, the Intonational phrase, the Accentual phrase, the Word and the Syllable. Our results show that although durational effects of prosodic boundary are still very strong, the effects on supralaryngeal articulation and on spectral characteristics are not as clear as those for the vowel /a/ reported in our previous work (Tabain, 2003a, 2003b). For instance, no effects are observed on the jaw or on F1 or F2. However, differing effects observed on tongue body articulation for male and female speakers together with the same effect on F3 for all speakers suggest that speakers aim for an acoustic/auditory target rather than an articulatory target when producing /i/ at stronger boundaries. These articulatory and acoustic results are argued to reflect featural enhancement of /i/ in French at stronger boundaries, since French has a particularly crowded vowel space in the high front region.