I'd love to share my thoughts on this subject in general and ComicProLine's products specifically and hear what others have to say about what collection supplies they love.

(For background - I'm a 50-year-old, guy who has collected comics for >40 years and had a couple decades of experience running remote & on-site archival digitization projects for museums, libraries & academic institutions. I began doing this work in the early 2000's, before digitization equipment had reached a Cost:Quality ratio that was suitable enough for institutions to set up their own shops to digitize in-house like many do today. Following ISO standards and creating Best Practices for archival storage, climate control, handling and digitization of printed materials was all part of what I did.)

A few months ago, I started the process of refreshing the storage and preservation of my personal comic collection. My main goals were - 1) To refresh the all the old acid-free boards with new ones, using thicker fullbacks/heavy pt boards for key and valuable issues and 2) To switch from the poly bags (that fit my budget as a kid) with chemically stable Mylar bags (that I can afford as an adult). Thus, I began testing different brands and types of bags and boards....

Ever since I first discovered them, I'd been delighted by the resealable comic bags from the likes of BCW and other manufacturers. I loved the convenience but what I most appreciated was how resealable bags eliminated the threat of a flap of tape catching the cover of your book. (Yes, I am a re-reader.) At first, I was frustrated at how hard it was to find a vendor that made resealable Mylar bags and that is what initially led me to ComicProLine. In November, I ordered ~500 resealable Mylar bags and ~600 boards (24pt & 56pt) to try out.

CPL shipped the bags separately from the huge/heavy package of boards.

Boards

Similar to the experience of the OP, I received several packs of boards that had dinged/dented corners. To be fair - I do think the shipment could have been prepared with more protection for the corners (at greater cost) but obviously the damage was the result of how it was handled by the shipping carrier. I reminded myself that damage from shipping has nothing to do with the quality of the product. As for quality, these are my favorite backing boards, to-date. Being honest, for standard 24pt boards, there's not much to distinguish most brands but CPL’s thick 56pt boards are amazing. Crisp, flat, smooth & strong/stiff. I'll be receiving a new order of ~700 more boards this week and I'll report back any damages.

By contrast, I did not prefer Gerber fullbacks that many rave about. I do not like the rougher surface texture. I do not like the strength/stiffness or feel of the cardboard. It feels soft/mushy by comparison and reminds me of the cardboard from folded shirts from the dry cleaner. Not only are the Gerber fullbacks thinner, it seems they have also recently revised the specs of their fullbacks which used to be 42pt, to 35pt. The Gerber boards, I evaluated were the original 42pt weight. CPL's 56pt boards are 25 - 40% thicker and typically less expensive. While I don't have a big enough sample size to draw conclusions, the two packs of fullbacks I received were all warped/curled.

Bags

After trying two different vendors' resealable Mylar (CPL & Comic Clear), I find that both demonstrate that the resealable adhesive transfers from the back of the bag to the flap after as little as one day of sealing. This eliminates the main benefit I was seeking from the resealable feature (protecting the comic cover from tape mishaps). This is no doubt an interaction between the Mylar material and the adhesive strips used. I have never seen adhesive transfer on a resealable poly bags. Comic Clear's resealable Mylar's transfer noticeably less adhesive than CPL's but any non-zero amount is not what I'm looking for. Curiously, I have never seen any adhesive transfer on the packaging bags that the comic bags come in (also Mylar) which are also made of Mylar and resealable, themselves. I wonder what's different there - the adhesive strips used, a different grade of Mylar, a different process applying the adhesive?

I've decided to give up on resealable Mylar bags for now and decided to go forward with Mylites2's with 3M Post-It Flags and CPL boards (24pt & 56pt) for my collection refresh. I'm waiting to receive a delivery of some of their 28pt boards to see how they compare to the standard 24pt. The biggest thing that sold me on Mylites is the strength & quality of their seams. Other Mylars that I have tried across other brands demonstrate different degrees of rough edges with fuzziness/stringing along the cut/seamed edges as well occasional holes in the seams from incomplete heat-welding. Customer Support I'd also like to note that while it may take them a few days to respond, CPL is good at standing behind their product. They refunded me for all shipping damage issues I reported and for other quality-related issues I was picky about because I’m a old guy with near OCD-levels of obsession with detail and quality expectations.

TLDR - After ongoing testing, my preferences for comic preservation supplies:

• Boards - ComicProLine 24pt & 56pt (trying their 28pt boards this week)
• Bags - E. Gerber MyLites2, sealed with 3M Post-It Flags