Most baby cradles come with very thin or hard mattresses. However, you can increase your baby's comfort by making your own baby cradle mattress. Assuming you already have the sewing machine, needles, pins and scissors, the project will cost between $20 and $30. Your neighborhood fabric store has the necessary supplies for the job.
Prepare the first pattern. Your cradle probably already has a mattress. If so, place the store-bought mattress on the tracing paper and trace the shape of the mattress with a fine-tipped marker. If the cradle did not come with a mattress, place the bottom of the cradle's basket on the tracing paper and trace the shape of the basket with the marker.
Prepare the second pattern. If your first pattern was traced from the cradle's store-bought mattress, lay your second piece of tracing paper over the pattern. Trace the shape of the pattern, adding an extra 1/2 inch all the way around. If your first pattern was traced from the cradle's basket, lay your second piece of tracing paper over the pattern, then trace the shape of the pattern 1/2 inch inside the shape. You should now have two patterns, one of which is 1 inch wider and longer than the other.
Cut the foam. Cut out the smaller pattern; this is your pattern for the foam. Place the cut pattern on top of the foam and secure the pattern to the foam by pushing fabric pins through the paper into the foam. Cut the foam to the shape of the pattern with your heavy-duty scissors. Measure the circumference of the cut foam with a tape measure and make note of the measurement.
Cut the fabric for the mattress cover. Fold your flannel-backed vinyl in half and position the larger pattern on the folded fabric as close to one edge as possible. Secure the pattern to the folded fabric with fabric pins. Cut the fabric to the shape of the pattern. If the fabric is too thick to push the pins through it or to cut through it, cut the two pieces one at a time. Add 1 inch to the foam's circumference measurement (from Step 3), and cut a strip of the fabric that length by 2 1/2 inches wide: this will be used for the sides of the mattress cover.
Sew the mattress cover. Fold the strip in half, vinyl sides together. Sew the ends together with 1/2 inch seam allowance. Press open the seam with a cool iron. The strip should now resemble a loop and will be the sides of the mattress cover. Pin one edge of the strip (loop) to the mattress cover bottom, vinyl sides together, leaving 8 inches unpinned. Pin the other edge of the strip (loop) to the mattress cover top, vinyl sides together, all the way around. With 1/2 inch seam allowance, sew the bottom to the side, except for the unpinned 8 inches. Sew the top to the side all the way around with 1/2-inch seam allowance. Trim away 1/4 inch of the seam allowance all the way around. Turn the mattress cover right side out.
Put the cut-out foam into the mattress cover and keep adjusting it until the foam fits nicely within the cover and there are no bulges. To sew shut the 8-inch opening in the mattress cover, tuck under the open edges 1/2 inch and pin it shut with fabric pins. Thread the hand-sewing needle with heavy-duty thread and sew the pinned area shut using a slip (blind) stitch.