You don't need museum quality framing for everything but when you do it's nice. Museum quality consists in several steps and procedures insuring the artwork's safe handling during the framing process and it's preservation long after.
In this example, an original watercolor by Michael Hague the framing package (backing, mats, and glass) is sealed by pH neutral linen tape around the parameter to keep out bugs and mitigate the off gassing of the wood frame (if any) passing through to the artwork. The linen tape is also used to hinge the 100% rag mat to the barrier paper that houses the work, held in place by archival corners. One of the most important hallmarks of museum quality framing is that all of the adhesives and tapes are pH neutral and archival quality. Conservation grade glass and a Roma profile finish the job with stunning results.