Sewing coasters is one of the easiest fabric projects to start with
A coaster is a small square or rectangle of fabric, usually four by four inches, sewn together from two pieces with batting or interfacing sandwiched between them. You sew three sides closed, turn it right-side out through the fourth side, then stitch that opening shut. The whole project takes 20 to 30 minutes once you have your materials cut. Because coasters are small, mistakes are forgiving, and you use up fabric scraps instead of buying yardage.
You need a sewing machine, thread, fabric scissors, a needle for hand-sewing the final opening, and fabric. The fabric can be cotton quilting squares, old t-shirts, linen napkins, or any woven material you have. Batting (the fluffy middle layer) comes in packages at any fabric store and costs a few dollars. You do not need a pattern — just a ruler and a pencil to mark your squares.
Key Takeaways
- Cut two fabric squares and one batting square to the same size, usually four by four inches, and mark a quarter-inch seam allowance with a pencil before sewing.
- Sew three sides of the coaster on your machine using a straight stitch, then trim the corners at an angle to reduce bulk when you turn it right-side out.
- Turn the coaster through the unsewn fourth side, poke out the corners with a blunt tool, and press it flat with an iron before closing the opening by hand.
- Hand-stitch the final opening closed using a ladder stitch, which hides the seam inside the fold and leaves no visible thread on the outside.
- Topstitch around the edge of the finished coaster one-quarter inch from the seam to hold all layers in place and add a professional-looking border.
Gather your materials and cut the pieces
Start by collecting two pieces of fabric cut to the same size. Four by four inches is standard, but you can make them three by three or five by five if you prefer. Use a ruler and a sharp pencil to mark your squares on the wrong side of the fabric — the side that will not show. Mark lightly so the pencil does not bleed through to the front.
Cut one piece of batting to the same size as your fabric squares. Batting is the layer that gives a coaster its thickness and helps it absorb water. If you cannot find batting, you can use a layer of flannel, fleece, or even a folded piece of muslin. Stack your two fabric pieces with the batting between them, right sides facing out. The batting should be sandwiched in the middle, and the two fabric pieces should be facing each other on the outside.
Before you sew, mark a quarter-inch seam allowance around all four sides of your stack. A seam allowance is the space between the edge of the fabric and the line where your needle will go. Use your ruler and pencil to draw a light line one-quarter inch in from each edge. This line is where your sewing machine needle will follow.
Sew three sides on the machine
Thread your sewing machine and set it to a straight stitch with a medium stitch length — about 2.5 millimeters. Place your coaster stack under the presser foot with the needle positioned on your quarter-inch line. Lower the presser foot and begin sewing slowly, following the line you marked. Sew along one complete side, then pivot at the corner by leaving the needle down, lifting the presser foot, and rotating the fabric 90 degrees. Lower the presser foot and continue sewing the next side.
Sew three complete sides this way. When you reach the end of the third side, backstitch — sew backward for a few stitches — to lock the thread. Leave the fourth side completely unsewn. This opening is where you will turn the coaster right-side out later. Before you remove the coaster from the machine, trim the corners at a 45-degree angle, cutting away the excess fabric about one-eighth inch from the corner seam. This step reduces the bulk of fabric at the corners and makes them lie flat when you turn the coaster right-side out.
Turn the coaster and press it flat
Carefully turn the coaster inside out through the unsewn fourth side. Use your fingers to gently push the fabric through the opening. Once it is turned, use a blunt tool — a chopstick, a wooden spoon handle, or a seam roller — to poke out each corner from the inside. Push gently so you do not poke through the seam. The corners should now form sharp right angles instead of rounded bulges.
Lay the coaster flat on an ironing board and press it with a warm iron. Press all four seams flat, paying special attention to the corners. As you press, use your fingers to gently fold the raw edges of the unsewn fourth side inward one-quarter inch, as if you were preparing to sew it closed. Press these folded edges flat as well. This step makes the final hand-sewing much neater because the raw edges are already tucked inside.
Hand-stitch the opening closed with a ladder stitch
Thread a hand-sewing needle with thread that matches your fabric. Tie a knot at the end of the thread. The ladder stitch, also called a slip stitch, hides the thread inside the fold of the fabric so no stitches show on the outside of the coaster. Start by bringing your needle up through the fold of fabric on one side of the opening, so the knot stays hidden inside. Bring the needle across the opening and insert it directly into the fold on the opposite side, sliding the needle inside the fold for about one-quarter inch before bringing it back out.
Go back across the opening and repeat on the first side, sliding the needle inside the fold again. The thread will form a ladder pattern inside the fold, and the opening will close as you pull the thread snug every few stitches. Continue until the opening is completely closed, then tie off the thread inside the fold and trim the excess. The outside of the coaster will show no visible stitches on this final seam.
Topstitch around the edge for a finished look
Place the coaster back under your sewing machine presser foot. Set the machine to a straight stitch again. Sew around all four sides of the coaster, staying one-quarter inch in from the edge. This topstitching holds all three layers — the two fabric pieces and the batting — together permanently and adds a decorative border that looks professional. Backstitch at the beginning and end to lock the thread.
If you want to add more visual interest, you can topstitch a second line one-half inch from the edge, or sew an X from corner to corner. These extra lines are purely decorative and help keep the batting from shifting inside the coaster over time. Once the topstitching is done, your coaster is finished and ready to use.
Troubleshooting common sewing mistakes
If your corners are rounded instead of sharp, you did not trim them before turning, or you did not poke them out enough after turning. You can still fix this by pressing harder with the iron and using a pointed tool to work the corners into shape. If your seams are wavy or uneven, you were not following your marked line closely enough, or your machine tension was too loose. Check your machine manual for how to adjust tension, and practice on scrap fabric before starting another coaster.
If the batting is bunching or shifting inside the coaster, you did not topstitch, or your topstitching was too far from the seams. Topstitching holds everything in place, so do not skip this step. If your hand-stitched opening is visible on the outside, you did not fold the raw edges in far enough before closing. Next time, fold them in a full half-inch and press them well before you start hand-sewing.
Frequently Asked Questions
Do I have to use batting, or can I just sew two pieces of fabric together?
You can sew two pieces of fabric together without batting, but the coaster will be thin and will not absorb water as well. Batting adds thickness and absorbency. If you do not have batting, use flannel, fleece, or even a folded piece of cotton fabric as a substitute.
What kind of thread should I use?
Use all-purpose polyester or cotton thread in a color that matches your fabric or blends in. The thread color matters most for the topstitching and the hand-stitched opening, where it will be visible. For the machine seams, thread color is less important because those seams are hidden inside.
Can I make coasters from knit fabric like jersey or fleece?
Knit fabrics are stretchy and harder to sew neatly, so woven fabrics like cotton, linen, or quilting cotton are better for beginners. If you want to use knit fabric, stabilize it first by fusing interfacing to the back, which prevents stretching and puckering.
How do I make sure my coasters are waterproof?
Fabric coasters are absorbent by design, not waterproof. If you want waterproof coasters, seal the finished coaster with a fabric-safe waterproofing spray, or back it with vinyl or oilcloth instead of regular fabric on one side.
Can I make coasters on a serger instead of a regular sewing machine?
Yes, a serger works well for coasters and finishes the seams neatly at the same time. Use a four-thread serger stitch on three sides, then turn and close the opening by hand as you would with a regular machine.