Yes they have all been self-adhesive type.
Brian, according to the 2015 Scott US Specialized catalog, the $1.00 and $2.00 wave stamps do not soak. However, Scott does not have the warning symbol with the listings for the $5.00 and $10.00 wave stamps. Maybe Scott has updated this for Scott #4717-4720? Someone with a newer catalog may be able to confirm.
If that symbol remains off the two high values, you'll still be taking a chance util you know for sure how the stamp soaks.
re: 2012 & 2015 Wave stamps
Yes they have all been self-adhesive type.
re: 2012 & 2015 Wave stamps
Brian, according to the 2015 Scott US Specialized catalog, the $1.00 and $2.00 wave stamps do not soak. However, Scott does not have the warning symbol with the listings for the $5.00 and $10.00 wave stamps. Maybe Scott has updated this for Scott #4717-4720? Someone with a newer catalog may be able to confirm.
If that symbol remains off the two high values, you'll still be taking a chance util you know for sure how the stamp soaks.