# Pressure ## Overview **Pressure** is the physical force being exerted on its tip. ## Key concepts * **The pen senses pressure**, not the tablet. The pen communicates the pressure it detects to the tablet. * The [IAF](https://docs.sevenpens.com/drawtab/core/pressure/iaf) is the smallest amount of pressure that an EMR pen will detect and report. * The [Pen pressure range](https://docs.sevenpens.com/drawtab/core/pressure/pen-pressure-range) is the range of physical force the pen is capable of sensing and outputting as pressure. In other words its lower bound is the IAF and its upper bound is the **maximum pressure**. * A tablet splits up the pressure range into a number of segments that are called [Pen pressure levels](https://docs.sevenpens.com/drawtab/core/pressure/pen-pressure-levels). * The [Pen pressure response](https://docs.sevenpens.com/drawtab/core/pressure/pen-pressure-response) is the pen hardware's "pressure behavior" - how a specific pen maps the physical pressure (how hard you are pressing down) to a logical pressure number that is sent to your computer. * A [Pen pressure curves](https://docs.sevenpens.com/drawtab/core/pressure/pen-pressure-curves) is a way of modifying or processing the pressure response of a pen. You can do this to solve or mitigate some kinds of pressure problems or to achieve certain kinds of creative effects. * A [Pressure curve dead zones](https://docs.sevenpens.com/drawtab/core/pressure/pen-pressure-curves/pressure-curve-deadzone) is a way of using a pressure curve to effectively increase the IAF. * The vast majority of drawing tablet pens are too-sensitive to small changes in physical pressure near the IAF. This means there is some [Drawing at low physical pressure](https://docs.sevenpens.com/drawtab/core/pressure/drawing-low-pressure). You can address this by using [Pen pressure curves](https://docs.sevenpens.com/drawtab/core/pressure/pen-pressure-curves) or **pressure smoothing**. * [Tilt affects pressure](https://docs.sevenpens.com/drawtab/core/pressure/tilt-affects-pressure). The pen is more sensitive when it is held perpendicular to the tablet surface. ## "Under pressure" video series If you'd prefer to watch, I built the "Under Pressure" video series on YouTube that goes deep into how pressure works. It explores all these concepts in great detail. {% embed url="" %} ## Relationship between the pen and the tablet * The pressure sensing mechanism is in the Pen, not the tablet. * Tablets do play a role in processing pressure. Tablets * Determine the number of pressure levels * Translate the pressure information from the pen into those levels * May process the pressure data before it is sent to the computer ## Units When dealing with the pressure (i.e. the force applied to the tip), the standard unit used is **gram force** abbreviated as **gf**. You may occasionally see this force described as **grams** and see the unit **g** used. This is technically incorrect, since grams are a unit of mass, not force. ## Disabling pressure Sometimes it is useful to disable pen pressure. For options on how to do so go here: [Disabling pen pressure](https://docs.sevenpens.com/drawtab/core/pressure/disable-pen-pressure). ## How EMR pens measure pressure There are two different techniques. The newer technique involves a pressure sensor in the pen. More here: [EMR pressure detection](https://docs.sevenpens.com/drawtab/tech/emr/emr-pressure-detection) ## Notes * Pens - even if they are of the same model - differ a little in their pressure sensitivity * Pressure sensors are subject to wear. Over time, you may find that a pen is less sensitive to pressure than it used to be. Though in practice, I have never experienced this in any noticeable way myself. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.sevenpens.com/drawtab/core/pressure.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.