A lap blanket is a quick and easy crochet project when you use a large hook and a thick yarn. You don't need a printed pattern; just a little math will help you to design a pattern of your own. If you know how to make some basic stitches, you can create a warm, colourful blanket that will be pretty and practical. .
Lap blankets come in many sizes. Some are as small as 32 inches by 35 inches, and others are as large as 44 inches by 55 inches. It's easy to adjust a pattern to the size you like. If you're making the lap blanket for a specific person, take a few measurements when she's in a sitting position. Measure from her waist to her knees, then from her knees to the floor to estimate the length needed. Measure from one side of the chair to the other for the width.
If you're crocheting a lap blanket as a gift and you can't take measurements, use width and length sizes of 42 inches each, which will result in a generously-sized blanket.
Material and Pattern Choices
When choosing yarn, consider the finished weight of the lap blanket you're making. Four-ply yarn, when crocheted in a tight pattern, will produce a heavier blanket than three-ply or sports yarn. Yarn texture and finish will also influence your choice of material. There's a multitude of speciality products on the market, from eyelash yarns that result in a longhair effect to soft chenille yarns that are thick and chunky.
Any crochet stitch, or combination of stitches, can be used for a lap blanket. Use a double or triple crochet for an easy, quick project. Since the lap blanket is a square or rectangle, you can create a pattern that alternates an even number of double or triple crochet stitches with an even number of skipped stitches to create open areas. Think about the way the lap blanket will be used. If it's needed more for modesty than warmth, an airy, lacy pattern with open areas will serve the purpose. If the lap blanket is needed primarily to provide warmth, a tighter pattern with few or no skipped stitches or open areas will work best.
Rather than using a printed pattern, you can determine how many stitches you need and simply work in double or triple crochet until you reach the desired length. Make a sample using your chosen yarn and a size H hook to determine how many stitches per inch you crochet, then multiply that number by the width measurement. When you make your foundation chain, add two stitches for double or three stitches for triple crochet, and skip them when you start your first row.
You can use any combination of single, double and triple crochet to vary the pattern and add some interest. Work a row or two in a different colour yarn at intervals, or make the lap blanket in blocks of colour by crocheting the first third, then changing yarn, and repeating after the second third.