Velcro is a surface-to-surface contact attachment technology that resists separation in all directions and is removable with sufficient separation force. Ideal velcro is light-weight, thin, long-lasting, silent, easy to attach, and has a balanced separation force that is strong enough for the application yet weak enough for ease of use.
Modern generic-quality velcro is noisy, painful to touch, and loses strength over time. It is not recommended for applications with frequent cycling and human contact.
Symmetric mushroom designs are considerably more quiet but slightly less easy to attach. See 3M Dual Lock Reclosable Fasteners.
Zippers are a line-to-line removable attachment technology that resists separation in all directions and operates with a device along the joining path. Ideal zippers are light-weight, durable, silent, smoothly operable, and easy to grab the joining device.
You may be enticed to use bare metal zippers for their durability. Generic metal zippers are not recommended because they have a cold touch, mild clang, and painful edges. Select the metal zippers that have rounded edge construction; a bit of cold and clang is tolerable but pain is absolutely unacceptable- it will sharply decrease your product's value.
YKK Zippers are renowned worldwide for their quality. Unit cost per ~75cm segment mostly varies around $1 to $5 USD depending on zipper type and order quantity.
Loop clamps come with different mechanisms, including worm-drive, twist-wire, belt-buckle (incl. zip-tie), pinch, bolt, quick-release, spring, and snap-grip.
Zip ties are the most common clamp type. They have a strong mechanism so even generic zip ties can be quite robust. That said, beware overestimating their strength for industrial applications. Plastic zip ties have notoriously degraded in the heat and cold of diesel engine internals, causing extremely costly delays and damage. High quality plastic zip ties are generally only appropriate for cable organization and supplementary indoor uses.
For outdoor environments, the standard recommendation is the stainless steel worm-drive clamps. Get the ones with enhanced vibration resistance for particularly dynamic applications. Get the smooth belt-buckle clamps for tight spaces. For extreme environments, use solid-frame bolt clamps with a thread-locking fluid.
Screws, Nuts & Bolts
Screws are simple to install, but risk thread-stripping on the frame that is hard to repair.
Nuts and bolts are modular and relieve the thread-torque limitations of the frame, but require 2-sided access and risk scattered parts more easily.