Being unable to middle mouse click knives to open new tabs is a usability dealbreaker for me. Wrap the image with links, not binding awkward events.
It'll also reduce your load a bit, as I won't have to continuously reload the grid page of 50 knives just to look at one.
Some other suggestions:
* If I search handle material "micarta" I get a whole bunch of distinct incarnations, like "micarta, ash wood burl" and "bone, micarta, wood". Tokensise each term in the material type and return them as groups. "micarta" should have both of those, as should "wood", and ofc "bone" would distinguish them.
* For brand search, populate the list alphabetically or something. It's nice to have a list to scroll to explore. I have no idea what options are available other than a few brands I already know. If the goal is to find and explore the 60k knives there, I need some help.
* Sanity check the knife stats. There are going to be zero knives with a blade thickness of 1", nevermind 5". An example of one that shows up here is this knife: https://www.knifegeek.io/blades/boker-121589 which I presume you scraped from here: https://www.boker.de/en/vollintegral-2.0-jaeger-gold-121589#... but you should maybe have a secondary scrape for stats that are impossibly beyond params. Here seems to have the correct blade thickness: https://www.knifecenter.com/item/BO121589/boker-jager-gold-v...
* From the knive page, present tags to re-broaden the search. Using that same knife example, the navigations is currently: `Blades -> Boker Jager Gold Vollintegral ...` which is useless. It's a knife in the category of knives on a knives website. I'd like to be able to navigate back by type / brand etc.
It helps the exploration. I might find something I think has nice features and want to explore that set more.
* An obvious one I'm sure you have planned, but there are much more crucial and interesting features than the ones listed for filters. I care far far more about the general style of knife than I do blade thickness or handle material.
Fixed vs folding vs others is ofc vital.
Within the category of folding, the type of lock, if any.
Blade shape, a no brainer.
Nice to have overarching categories too. Rescue vs dive vs bushcraft would help immensely.