Here are my thoughts about tapes and their uses.
There are two parts to tape; the substrate (the tape itself) and the adhesive.
Tape can be made from wood pulp, cotton rag, linen and Japenese papers such as mulberry tissue.
Wood pulp contains lignin which will degrade over time and as it does it produces acid. The acid is what causes paper to discolour and weaken. Wood pulp needs to have all the lignin removed before it can be used in conservation framing but small traces can remain.
Tape made from cotton rag, linen cloth and Japeneses papers are all naturally lignin free so they make for a much better choice in conservation framing.
Adhesives fall into two categories; sticky self adhesive (pressure sensitive) and water activated (gummed). Self adhesive tape is pressure sensitive so the best bond is achieved by burnishing the tape after application. Self adhesive tape can fail in time and is not usually considered best practice for attaching directly to artwork.
Gummed tape needs to be activated with water for the adhesive to bond. Care needs to be taken not to apply too much or too little water. Gummed tapes are considered a better choice for conservation framing as they are less likely to fail.
Linen cloth tapes are available as pressure sensitive or gummed. They are a very strong tape and not usually recommended for making hinges for paper art as it is better to have the paper hinge weaker that the art itself. However, they are ideal for hinging together the window-mount and under-mount. Self adhesive is fine for this application as the tape is not in contact with the art.
Japanese mulberry tissues and similar are a popular choice for conservation framing as they are light and strong and come in different thicknesses and weights. However you need to apply your own adhesive which will usually be a freshly cooked wheat starch paste.
If you are just starting out in framing I would recommend using the cotton rag gummed tapes as much as possible to attach directly to artwork. Wet the tape with distilled or deionised water using a small brush. Use self adhesive linen cloth tape for hinging window-mounts to under-mounts.
Of course there are methods of attaching paper art to under-mounts without using any tape. For window-mounts a popular method is the platform mount.
For float mounting the usual method is pass through paper hinges or the hedgehog method. Double sided sticky pads, as I think you mentioned , are not a good idea.
Good luck with your new venture and keep asking plenty of questions on this great forum
