How we update koogel.org

What we update, how often, and the public sources behind the claims on our packs.

The catalog was last updated on October 23, 2026. That date covers the prices, the options on offer and the ratings you see on every product card of this site.

We update on a schedule. Each run asks again for every color, size and count of each of our products. A price that moved is replaced on the card, an option that ran out leaves the card, and a pack that comes back returns on the next update. If a price at checkout differs from the one on our card, the checkout price is the one you pay.

Counts, sizes, paper weights and ruling come from the product data of each pack. The calculators on our home page are arithmetic, and each one prints its rule next to the answer.

Four claims about materials appear on our packs, each only on the packs that carry it: FSC-certified materials, acid-free and lignin-free paper, a Children's Product Certificate on latex balloons, and food-grade, BPA-free silicone. The public sources below explain what each claim means. We read every one of them on October 23, 2026, and our journal articles link the sources they rely on.

Sources

FSC US, What do the FSC labels mean? What FSC 100%, FSC MIX and FSC RECYCLED labels say about the fiber in a paper product.
Library of Congress, The Deterioration and Preservation of Paper: Some Essential Facts. Why acid and lignin make paper yellow and brittle, and how to store paper that should last.
Library of Congress, Care, Handling and Storage of Photographs. The Photographic Activity Test and storage conditions for photographs in albums.
U.S. Consumer Product Safety Commission, Children's Product Certificate. What a Children's Product Certificate is, who issues it, and that it rests on tests by a CPSC-accepted laboratory.
Electronic Code of Federal Regulations, 16 CFR 1500.19, Misbranded toys and other articles intended for use by children. The federal rule that every latex balloon, and every toy or game containing one, must carry a cautionary statement about choking.
U.S. Food and Drug Administration, Bisphenol A (BPA). What BPA is: a chemical used in certain food contact materials, reviewed by the FDA.
Psychological Science in the Public Interest, Improving Students' Learning With Effective Learning Techniques (Dunlosky et al., 2013). The review of ten learning techniques that rated practice testing and distributed practice highest.
Applied Cognitive Psychology, Optimising learning using flashcards: Spacing is more effective than cramming (Kornell, 2009). Three experiments in which spacing beat cramming for 90% of learners, and one large stack beat four small ones.
Kansas State University Academic Achievement Center, Leitner System. How the Leitner system moves cards between stacks reviewed daily, every other day and less often.
Michigan Department of Environment, Great Lakes, and Energy, Recycling holiday giftwrap. Which gift wrap and tissue can go in curbside paper recycling, and why glitter and metallic wrap cannot.
U.S. Environmental Protection Agency, EPA Mid-Atlantic Administrator Offers Tips for an Environmentally-Friendly Holiday. The advice to avoid wrapping paper with plastic coatings or glitter, which is not typically recyclable.
U.S. Environmental Protection Agency, Paper and Paperboard: Material-Specific Data. Tissue paper among paper nondurable goods, and their recycling rate.
Utah Valley University Printing Services, Paper Primer: A practical Guide to Understanding Fine Printing Paper. Basic sheet sizes behind US paper weights, and why 80 lb cover and 80 lb text are different papers.
ISO, ISO 536:2019 Paper and board, Determination of grammage. The standard method behind a grammage figure in grams per square meter.

Questions about a figure: paperdesk@koogel.org. The way we write is set out in our editorial policy, and the thinking behind the Koogel way is on About Koogel.