For the cardboard:
You will need a 5" by 41/4" piece.
Measure 1/4 inch sections and draw lines to cut the 1/2" slots for the string.
Place the string through the first slot and bring to the front and across the front of the cardboard to the opposite slot.
After the string is placed in the second slot, bring the string back through the adjacent slot giving it what I will call "bunny ears".
Repeat these steps until all of the slots are full.
Starting from the right side of your work, weave under-over-under-over-etc. to the end.
Leave the end long.
Weave back through from the left just opposite of the previous weave (Your new weave should never match the previous weave.)
(If you are making the striped coaster, this is the pattern you will want to follow)
**ALSO: Make sure that you are not pulling too hard on the strands, causing the outer strings to bow in. This will make your coaster funny shaped.
Weave four strands left and right.
On the fifth strand (toward the left) finish the strand two strings in instead of going to the end.
This is the start of the pattern that you will repeat every two rows. until you run out of strings.
Flip your work over and do the exact opposite with the blue until it meets the other.
Weave the lose ends, covertly, back into your work to keep it from unraveling.
Taking the beige yarn, weave it through to the blue. Again, leaving the loose end to weave back through later.
Separate the ends of the existing rows to make it more obvious where to connect the rows.
Make sure that you are always interconnecting the seams.
Continue to the end and weave in the loose ends.
Cut the strings and tie them in pairs.
IMPORTANT: Do not remove all of the strings at once or it will come unraveled.
Cut one at a time and swap sides every 3 that you tie. This will ensure that your work stays secure.