* 1 Most suitable - Adhesives that fit this category are those which are known to bond well to the substrate selected and therefore there is a high chance that the bonding operation will be successful. However, as with all bonding operations, appropriate surface preparation and joint design are essential to obtain a good bond. In addition, all bonding recommendations arising from this selector should undergo extensive practical test trials matched to the needs of the fabricated device.

* 1 + 2 Suitable - This criteria includes those adhesives that fit category 1 AND additionally adhesives which fall into the 'Suitable' category. These adhesives have been shown to exhibit good bonding characteristics to the selected substrates in the majority of cases but there are instances where compatibility issues exist. Appropriate surface preparation, joint design and testing are essential prerequisites as described in option 1, before the adhesive can be deemed acceptable.

* 1 + 2 + 3 Possibly suitable - This criteria includes all adhesives from the first two options and also adhesives where an acceptable bond can be obtained either with specialised pretreatments such as etching or priming (e.g. polyolefins, fluorocarbons, silicones) or the bond will be of medium strength without specialist pre-treatment. An effort will be made to flag up material combinations where case a) is most relevant.