Shipping and Returns


We are happy to ship anywhere in the world.

Within the USA, we offer free shipping by USPS Media Mail. Shipping by USPS Priority Mail is available for an additional fee, depending on weight and distance.

We reserve the right to substitute similar shipping methods, such as FedEx ground.

We charge actual postage for international orders.

International Shipping Containers and Rates
Capacity Canada Rest of the World
Flat Rate Envelope Up to ~ $50 of books $22.75 $28.45 - $32.25
Flat Rate Box Up to ~ $150 of books $43.65 $63.60 - $72.15

The Elementary Set and College Set each ship in one flat-rate box. The College Prep Set ships in two flat-rate boxes. The Full Math Set ships in four flat-rate boxes and an envelope.

Up to three elementary books can fit into a flat rate envelope. Note that if you get say, six of them, the web site will put that into a box, so if you want it in two envelopes, place two orders for three books each. If you are planning to get all of the Elementary Set, it costs less in postage to get them all at once than to buy them piecemeal. Also, the box protects the books better from getting banged up than the envelopes do.


Your satisfaction with our products is our highest priority. If you are not satisfied for any reason, simply return the books in saleable condition within 35 days of your order date and we will issue you a refund. Please note that, once shipped, shipping charges are non-refundable.

Return merchandise to:

Z-Twist Books
3312 Woodview Dr.
Lafayette, CA 94549

Please include a copy of your packing slip with your return so we can tell where to send the refund.

Errors and Damage

We are only human. Errors in shipping and damage to merchandise do occasionally occur. Claims for errors or damage must be made within seven days of receipt of the merchandise.