Firms relying on external sources of knowledge for innovation may encounter a paradox of openness concerning the need to both share and protect knowledge in collaborations. Based on an international survey of manufacturing firms this study attempts to illustrate various forms of the paradox by investigating the effects firms’ openness has on appropriability and performance in high and low tech industries. Findings reveal that the paradox is more likely to occur in the high tech industry cluster, thus hinting towards additional challenges firms in this cluster face in practice and underlining the need to include the technological dimension when researching the paradox. Moreover, in the majority of openness-appropriability combinations where we find a potential paradox of openness, firms do not succeed to overcome the paradox. The one exception in our sample is for the high tech firms when collaborating with suppliers and using formal appropriability. By pinpointing the different forms of the paradox this study also contributes to the ongoing debate concerning the role of intellectual property mechanisms in inbound open innovation.