In one sentence, describe what the following article is about: Stamp catalogs and price guides are excellent resources, having illustrated lists of stamps, arranged by year, that give a current market value for a given stamp issue. The most widely recognized catalogs are: the Scott Postage Stamp Catalog, Stanley Gibbons for Great Britain issues, Yvert et Tellier for French issues, Unitrade for Canadian issues, and Minkus and Harris US/BNA for United States issues. You can often find these books in a large library, if you don't want to purchase them yourself. With the designs of many stamp issues only differing by a line or a dot, magnifying glasses are probably the stamp collector's most valued tool. Small jeweler's loops are effective for most hobbyists, but extra valuable or difficult to identify stamps could call for a high-powered magnifying glass with a built-in colored light source. This tool measures the size of the perforated holes around the edge of the stamp, and is only necessary for advanced stamp collectors. These gauges tell you how many perforations fit in 2 centimeters (0.79 inches), which can greatly affect the price of a valuable stamp. If a stamp guide lists two numbers, such as "Perf 11 x 12," the first number refers to the horizontal perforation and the second number refers to the vertical. The paper used to print stamps sometimes has a watermark, often too faint to identify by holding it up to the light. If you have a stamp that can only be identified with a watermark, you'll need a special watermark detection fluid that is non-toxic and safe for stamps. Place the stamp on a black tray and drip the fluid onto it to reveal the watermark. This is also a good way to find creases and hidden repairs on a stamp. If you don't want to get your stamps wet, purchase a specialized tool for this purpose, such as a Sinoscope or Roll-a-Tector.
Summary: Refer to stamp collector books. Examine stamps with a magnifying glass. Use a perforation gauge. Identify watermarks.

In one sentence, describe what the following article is about: Instead of using butter to cook your vegetables use olive oil. Depending on how much chopped vegetables you have, use tablespoon to 1 tablespoon of olive oil to cook your vegetables. You can add the oil to the pan prior to adding your vegetables or stir the vegetables in the oil in a bowl or Ziploc bag. While cooking your vegetables, you can also add in meats like chicken, fish, or beef. If adding in meat, start with a tablespoon of olive oil. You can also make a marinade for your meat with olive oil. This marinade works well with poultry, meat, and seafood. Place your meat in a pan and pour the marinade over it. Then, allow it to marinate for at least one hour. You can even marinate the meat overnight for a stronger flavor. Combine the following ingredients by whisking or blending: cup of fresh lemon juice teaspoon of pepper teaspoon of salt or to taste 3 crushed cloves of garlic cup of coarsely chopped fresh parsley cup of coarsely chopped basil, cilantro, dill, oregano, or other herbs you like. cup of EVOO. Extend the life of your cake and baked goods by using olive oil instead of butter. The vitamin E in olive oil preserves the freshness of baked goods. Substituting olive oil in your baked goods increases the monounsaturated fats, decreases saturated fats, and decreases cholesterol in the baked goods. If a recipe calls for a certain amount of butter, simply use cup of olive oil for every cup of butter. For savory breads and sweets such as cakes, cookies, and other desserts, use the lighter version of olive oil instead of EVOO. This lighter version has a neutral taste and can withstand high-heat cooking methods.
Summary: Stir-fry with olive oil. Marinate with olive oil. Bake with olive oil.

In one sentence, describe what the following article is about: Dry air can irritate an already sore throat. To introduce moisture, run a humidifier in your bedroom before you go to sleep or through the night. Keep the humidity around 49 to 50%. Some humidifiers have a cool mist or warm mist setting so you can control the temperature in your room more effectively. It's also a good idea to hydrate yourself just before bed. Drink a glass of water or set one on your bedside table. If mucus collects in the back of your throat by morning, raise your head up before you go to sleep. Elevating your head will help the mucus drain so it doesn't irritate your throat. Sleeping on your side with a pillow between your knees can also help prevent nasal drainage from irritating your throat. Although you might feel like bundling up if you have a cold, you'll actually fall asleep faster if your body is a little cool. Set your bedroom thermostat between 60 and 67F (16 and 19C) before you lie down. In the morning you can turn the heat back up if needed. It's also a good idea to sleep with blankets that you can take off if you get too warm. Keeping your room cool can help you sleep, but avoid using an air conditioner if you can. An A/C can dry out the air, further irritating your throat. Try to unwind during the hour before you plan to go to sleep. To make it easier to relax, keep the lights low and get comfortable. Practice your favorite calming techniques such as reading a good book, soaking in the tub, or meditating. Taking a steamy shower is another great way to relax before bed since it will loosen mucus and can relieve other symptoms of a cold. Avoid looking at bright screens or listening to loud music. Lie on your side to keep post-nasal drip from irritating your throat. Minimize irritants in the room such as tobacco smoke or cold, dry air.
Summary:
Run a humidifier before bed or while you sleep. Sleep with a few extra pillows under your head. Keep your room between 60 and 67F (16 and 19C). Relax in a dim bedroom before going to sleep.