Hi. Thank you for your inquiry:
Our UCT-50 (and there are a few others in this series UCT-XX) Double Coated Tape product would be the only Pressure Sensitive Adhesive product which we promote with visual clarity claims for general industrial applications. We do report typical properties however optical properties are not controlled or certified as specifications. But UCT-50 product does have great visual clarity and appearance and is presented on a double polyester release liner to be sure this level of visual quality is preserved prior to application.
Another less clear option would be 3M type 300LSE pressure sensitive adhesive products. Great performance to these substrates, slightly amber color although this slight color is typically not visible in single layers. There are a wide variety of constructions and thicknesses using type 3M 300LSE adhesive.
Here is the link to the first of many pages of info about 3M Products which contain type 300LSE adhesive.
There are also a selection of Specialty products specifically designed for Optical Clarity and display assembly. These did not seem to match your inquiry but wanted to at least mention them.
Questions or comments welcome.
Thank you for you interest.
3M Application Engineering Team